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

- In sunkbd_probe_keyboard() don't bother to determine the keyboard layout
as we have no use for that info. Instead let this function return the
keyboard ID and verify at its invocation in sunkbd_configure() that we're
talking to a Sun type 4/5/6 keyboard, i.e. a keyboard supported by this
driver.
- Add an option SUNKBD_EMULATE_ATKBD whose code is based on the respective
code in ukbd(4) and like UKBD_EMULATE_ATSCANCODE causes this driver to
emit AT keyboard/KB_101 compatible scan codes in K_RAW mode as assumed by
kbdmux(4). Unlike UKBD_EMULATE_ATSCANCODE, SUNKBD_EMULATE_ATKBD also
triggers the use of AT keyboard maps and thus allows to use the map files
in share/syscons/keymaps with this driver at the cost of an additional
translation (in ukbd(4) this just is the way of operation).
- Implement an option SUNKBD_DFLT_KEYMAP, which like the equivalent options
of the other keyboard drivers allows to specify the default in-kernel
keyboard map. For obvious reasons this made to only work when also using
SUNKBD_EMULATE_ATKBD.
- Implement sunkbd_check(), sunkbd_check_char() and sunkbd_clear_state(),
which are also required for interoperability with kbdmux(4).
- Implement K_CODE mode and FreeBSD keypad compose.
- As a minor hack define KBD_DFLT_KEYMAP also in the !SUNKBD_EMULATE_ATKBD
case so we can obtain fkey_tab from <dev/kbd/kbdtables.h> rather than
having to duplicate it and #ifdef some more code.
- Don't use the TX-buffer for writing the two command bytes for setting the
keyboard LEDs as this consequently requires a hardware FIFO that is at
least two bytes in depth, which the NMOS-variant of the Zilog SCCs doesn't
have. Thus use an inlined version of uart_putc() to consecutively write
the command bytes (a cleaner approach would be to do this via the soft
interrupt handler but that variant wouldn't work while in ddb(4)). [1]
- Fix some minor style(9) bugs.

PR: 90316 [1]
Reviewed by: marcel [1]

Start each of the license/copyright comments with /*-, minor shuffle of lines

Add a uart attachment/syscons keyboard driver for sun keyboards. In theory
this will work with any uart backend, currently supported hardware uses
either ns8250 or z8530.