sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

Remove "All Rights Reserved" from FreeBSD Foundation sys/ copyrights

These ones were unambiguous cases where the Foundation was the only
listed copyright holder (in the associated license block).

Sponsored by: The FreeBSD Foundation

sys/arm: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Allow us to be told about memory past the first 4GB point, but ignore it.
This allows, for example, UEFI pass a memory map with some ram in this
region, but for us to ignore it. This is the case when running under the
qemu virt machine type.

Sponsored by: ABT Systems Ltd

Implement OF_decode_addr() for arm. Move most of powerpc's implementation
into a new function that other platforms can share.

This creates a new ofw_reg_to_paddr() function (in a new ofw_subr.c file)
that contains most of the existing ppc implementation, mostly unchanged.
The ppc code now calls the new MI code from the MD code, then creates a
ppc-specific bus_space mapping from the results. The new arm implementation
does the same in an arm-specific way.

This also moves the declaration of OF_decode_addr() from ofw_machdep.h to
openfirm.h, except on sparc64 which uses a different function signature.

This will help all FDT platforms to set up early console access using
OF_decode_addr().

Retire machine/fdt.h as a header used by MI code, as its function is now
obsolete. This involves the following pieces:
- Remove it entirely on PowerPC, where it is not used by MD code either
- Remove all references to machine/fdt.h in non-architecture-specific code
(aside from uart_cpu_fdt.c, shared by ARM and MIPS, and so is somewhat
non-arch-specific).
- Fix code relying on header pollution from machine/fdt.h includes
- Legacy fdtbus.c (still used on x86 FDT systems) now passes resource
requests to its parent (nexus). This allows x86 FDT devices to allocate
both memory and IO requests and removes the last notionally MI use of
fdtbus_bs_tag.
- On those architectures that retain a machine/fdt.h, unused bits like
FDT_MAP_IRQ and FDT_INTR_MAX have been removed.

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

Initial FDT infrastructure elements for ARM.

Reviewed by: imp
Sponsored by: The FreeBSD Foundation