Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

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

Commit initial (unfinished!) support for the AR933x series of embedded
CPUs.

The AR933x is a mips24k based SoC with an AR9380 series SoC on board,
two gigabit ethernet interfaces and an internal 10/100mbit ethernet
switch. There's also the normal interfaces (USB, ethernet, uart, GPIO.)

The downside? There's a non-ns8250 UART device.

With a very basic UART driver (not in this commit) the SoC is initialised
and boots up. I'll commit the UART code soon and then link it into the
general setup path.

This code is a re-implementation based from the Linux kernel / openwrt
AR933x support.

TODO:

* UART (obviously)
* All of the ethernet, USB and wifi SoC glue, including ethernet PLL
programming.