ofwdump: install dependent on MK_FDT

The utility depends on the presence of the openfirm(4) pseudo-device,
which is gated by the FDT kernel option. The MK_FDT knob is correctly
set to "yes" for FDT/OFW-enabled platforms (powerpc* included); use it
to install the utility and eliminate the arch-specific Makefile logic.

No functional change intended.

Reviewed by: emaste, pkubaj
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D41977

Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

Create a new MACHINE_ARCH for Freescale PowerPC e500v2

Summary:
The Freescale e500v2 PowerPC core does not use a standard FPU.
Instead, it uses a Signal Processing Engine (SPE)--a DSP-style vector processor
unit, which doubles as a FPU. The PowerPC SPE ABI is incompatible with the
stock powerpc ABI, so a new MACHINE_ARCH was created to deal with this.
Additionaly, the SPE opcodes overlap with Altivec, so these are mutually
exclusive. Taking advantage of this fact, a new file, powerpc/booke/spe.c, was
created with the same function set as in powerpc/powerpc/altivec.c, so it
becomes effectively a drop-in replacement. setjmp/longjmp were modified to save
the upper 32-bits of the now-64-bit GPRs (upper 32-bits are only accessible by
the SPE).

Note: This does _not_ support the SPE in the e500v1, as the e500v1 SPE does not
support double-precision floating point.

Also, without a new MACHINE_ARCH it would be impossible to provide binary
packages which utilize the SPE.

Additionally, no work has been done to support ports, work is needed for this.
This also means no newer gcc can yet be used. However, gcc's powerpc support
has been refactored which would make adding a powerpcspe-freebsd target very
easy.

Test Plan:
This was lightly tested on a RouterBoard RB800 and an AmigaOne A1222
(P1022-based) board, compiled against the new ABI. Base system utilities
(/bin/sh, /bin/ls, etc) still function appropriately, the system is able to boot
multiuser.

Reviewed By: bdrewery, imp
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D5683

Make the building of libsmb and mount_smbfs unconditional, now that r292552
has eliminated alignment and endian problems that were making it fail on
some platforms.

PR: 180438
PR: 189415

- Trim an unused and bogus Makefile for mount_smbfs.
- Reconnect with some minor modifications, in particular now selsocket()
internals are adapted to use sbintime units after recent'ish calloutng
switch.

Disconnect non-MPSAFE SMBFS from the build in preparation for dropping
GIANT from VFS. In addition, disconnect also netsmb, which is a base
requirement for SMBFS.

In the while SMBFS regular users can use FUSE interface and smbnetfs
port to work with their SMBFS partitions.

Also, there are ongoing efforts by vendor to support in-kernel smbfs,
so there are good chances that it will get relinked once properly locked.

This is not targeted for MFC.

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Merge from tbemd: use Makefile.arch to control building.

Reviewed by: arch@ (many times, no objection)