MFC r325834,r325997,326502: Move sys/boot to stand/

This is effectively a direct commit to stable/11, due to differences between
stable/11 and head. Changes to DTS in sys/boot/fdt/dts were often
accompanied by kernel changes. Many of these were also risc-v updates that
likely had many more dependencies to MFC.

Because of this, sys/boot/fdt/dts remains as-is while everything else in
sys/boot relocates to stand/.

r325834: Move sys/boot to stand. Fix all references to new location

r325997: Remove empty directories.

r326502: Document the sys/boot -> stand move in hier.7 and the top-level README.

MFC Loader Fixes 2017q4p6: r324649,r324650,r324651,r324652,r324653,r324654,
r324700,r324702,r324709,r324717,r324719,r324841,r324842,r324843,r324845,
r324850,r324876,r324877,r324878,r324879,r324880,r324881,r324883,r324980,
r324981,r324982,r324995,r325014,r325093,r325094,r325114,r325170,r325171,
r325172,r325173,r325174,r325175,r325176,r325248,r325286,r325310,r325332,
r325338,r325339,r325376,r325377,r325379,r325380,r325382,r325478,r325479,
r325480,r325482,r325483,r325484,r325485,r325556,r325641,r325681,r325685,
r325686,r325687,r325688,r325689,r325690,r325691,r325692,r325693,r325694,
r325743,r325744,r325748,r325775,r325779,r325780

r324649: Move common/Makefile.inc to sys/boot/loader.mk.

r324650: tweak style

r324651: create defs.mk for common definitions

r324652: Move all the ficl common code into ficl.mk

r324653: LOADER_foo_SUPPORTED

r324654: Explicitly inlcude SYSDIR in the include path

r324700: loader: initialize dv_cleanup in md.c to eliminate clang warning

r324702: We need to include disk.o in libuboot.a when we're building with
support for disk access.

r324709: Revert "Unify boot1 with loader" change r324646

r324717: libsa/ip.c: misplaced comment, ip_v is half char, not ip_p

r324719: libsa/ip: stop read loop on bad fragments

r324841: Use BOOTDIR more consistently in defs.mk rather than repeat
sys/boot.

r324842: Introduce BOOTOBJ: The top level object directory for the boot tree

r324843: Stopgap fix to the mistmatch between LOADER_GELI_SUPPORT and
LOADER_NO_GELI_SUPPORT.

r324845: Use BOOTOBJ and BOOTDIR to find geli includes and libraries.

r324850: Define LIBSA32 to LIBSA on i386 to fix build.

r324876: Move fdt and uboot defines into common uboot.mk.

r324877: End source directories with SRC rather than a hodgepodge of names

r324878: Make at91 boot loader compile again.

r324879: Prefer SRCTOP paths for bits we're grabbing from libc.

r324880: Use BOOTSRC here.

r324881: Use SYSDIR instead of ${.CURDIR}/../..<etc>/sys.

r324883: Use preferred defined paths, rather than relative paths in fdt.

r324980: Use BOOTDIR consistently.

r324981: Move BINDIR definition to defs.mk, and override where it isn't
/boot

r324982: Remove sys/boot/arm/at91 and ixp425

r324995: loader.efi: Make framebuffer commands available for arm64

r325014: Add a 'place holder' arm struct efi_fb until a real one comes

r325093: Define new EFI variables

r325094: Cleanup non-arch Makefiles

r325114: Use defs.mk defins in most MD code

r325170: Use defs.mk values for userboot

r325171: Use defs.mk name and prefer bsd.init.mk

r325172: Remove the -nostdlib stuff I added. Instead, fix LDFLAGS to be
honored correctly with the new Makefile.inc include order.

r325173: We don't need to build a special ficl for userboot.

r325174: Minor cleanup

r325175: For amd64, compile both zfs and zfs32 libraries.

r325176: Actually add zfs32/Makefile

r325248: loader ptblread() is broken with >512B sectors

r325286: efipart_strategy is using wrong offset with >512B sectors

r325310: zfs.c:vdev_read() needs to be careful about large sectors

r325332: loader: re-enable gzip support for x86

r325338: loader: fix BOOTSRC -> BOOTOBJ in a library path

r325339: This used to have bzip2 support too.

r325376: WIP: centralize machine links

r325377: mostly libsa

r325379: Revert "mostly libsa"

r325380: Revert "WIP: centralize machine links"

r325382: Cleanup stray libstand names to be libsa names.

r325478: Powerpc is a 32-bit boot loader.

r325479: Define LIBFICL32 to be libficl.a on i386 and libficl32.a on amd64.

r325480: Use DO32 for all the places that we need to flag we're building a
32-bit version of a library.

r325482: Move machine and other link creation to defs.mk

r325483: MACHINE can never be powerpc64, so cleanup code that thinks it can.

r325484: Prefer bsd.init.mk to src.opts.mk

r325485: Centralize all 32-bit builds on 64-bit platform stuff.

r325556: loader: set options before including bsd.init.mk

r325641: loader.efi: efi_devpath_is_prefix should return bool

r325681: boot1: avoid using NULL device path

r325685: libsa32 isn't needed for i386. It's already a 32-bit platform.

r325686: Simplify this if to a direct assignment.

r325687: Remove all the empty help files from the powerpc build.

r325688: FDT support doesn't make sense for ps3, remove it.

r325689: Remove LOADER_FDT_SUPPORT as a Makefile variable.

r325690: Remove LOADER_ZFS_SUPPORT as a Makefile variable

r325691: Remove useless PNP define here.

r325692: Replace LOADER_FIREWIRE_SUPPORT variable

r325693: Move LOADER_{NO,}_GELI_SUPPORT to MK_LOADER_GELI

r325694: Install the 4th files in sys/boot/forth instead of each loader

r325743: Make sure the proper loader.rc gets installed.

r325744: boot1: also check for NULL device

r325748: Use proper include file.

r325775: Add loader.conf to the list of files that are MD.

r325779: Add /boot/dts to the list of default modules.

r325780: Don't add /boot/dt*s* but /boot/dt*b*. Stupid think-o.

MFC Loader Fixes 2017q4p4: r324552,r324553,r324554,r324555,r324556

r324552: Kill the userboot copy of libstand.

r324553: Rename libstand.a to libsa.a and libstand32.a to libsa32.a

r324554: Move crc32.c, util.c and gpt.c over to libsa.

r324555: Honor CFLAGS modifications in Makefile.inc by using += here.

r324556: Move ufsread.c

Rename libstand.a to libsa.a and libstand32.a to libsa32.a

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