MFC r306756:

ARM: SEV/WFE instructions are implemented starting from ARMv6K, use it
directly.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Almost all copies of platform_mp_init_secondary just called
intr_pic_init_secondary. Replace them with a direct call. On BCM2836
and ARMADA XP we need to add this function, but it can be empty.

Reviewed by: ian, imp
Sponsored by: ABT Systems Ltd
Differential Revision: https://reviews.freebsd.org/D5460

Remove platform_mp_probe as it's almost identical on most ARM SoCs, and
slightly wrong on the others. We should just check if mp_ncpus is set to
more than one CPU as we may wish to run on a single core even when SMP is
available.

Reviewed by: ian
Sponsored by: ABT Systems Ltd
Differential Revision: https://reviews.freebsd.org/D5458

Remove platform_ipi_send, it's an unneeded as all implementations are
identical.

Sponsored by: ABT Systems Ltd

ARM: Use new ARMv6 naming conventions for cache and TLB functions
in all but ARMv4 specific files.
Expand ARMv6 compatibility stubs in cpu-v4.h. Use physical address
in L2 cache functions if ARM_L2_PIPT is defined.

[intrng] Migrate the intrng code from sys/arm/arm to sys/kern/subr_intr.c.

The ci20 port (by kan@) is going to reuse almost all of the intrng code
since the SoC in question looks suspiciously like someone took an ARM
SoC design and replaced the ARM core with a MIPS core.

* migrate out the code;
* rename ARM_ -> INTR_;
* rename arm_ -> intr_;
* move the interrupt flush routine from intr.c / intrng.c into
arm/machdep_intr.c - removing the code duplication and removing
the ARM specific bits from here.

Thanks to the Star Wars: The Force Awakens premiere line for allowing
me a couple hours of quiet time to finish the universe builds.

Tested:

* make universe

TODO:

* The structure definitions in subr_intr.c still includes machine/intr.h
which requires one duplicates all of the intrng definitions in
the platform code (which kan has done, and I think we don't have to.)

Instead I should break out the generic things (function declarations,
common intr structures, etc) into a separate header.

* Kan has requested I make the PIC based IPI stuff optional.

Rename arm_init_secondary_ic() -> arm_pic_init_secondary(). The latter is
the name the function will have when the new ARM_INTRNG code is integrated,
and doing this rename first will make it easier to toggle the new interrupt
handling code on/off with a config option for debugging.

Include vm/pmap.h for pmap_kextract.

Add necessary changes to support various Amlogic SoC devices
specially aml8726-m6 and aml8726-m8b SoC based devices.
aml8726-m6 SoC exist in devices such as Visson ATV-102.
Hardkernel ODROID-C1 board has aml8726-m8b SoC.

The following support is included:
Basic machdep code
SMP
Interrupt controller
Clock control driver (aka gate)
Pinctrl
Timer
Real time clock
UART
GPIO
I2C
SD controller
SDXC controller
USB
Watchdog
Random number generator
PLL / Clock frequency measurement
Frame buffer

Submitted by: John Wehle
Approved by: stas (mentor)