Remove confusing, leftover comment.

The a2kbbc is now based on MI MSM6242B driver.

split device_t/softc for all remaining drivers.
replace "struct device *" with "device_t".
use device_xname(), device_unit(), etc.

branches: 1.23.2; 1.23.12;
CFATTACH_DECL_NEW, device_t, cfdata_t

branches: 1.22.2;
Remove clause 3 (UCB advertising clause) from the University of Utah
copyright. Confirmed by Mike Hibler, mike at cs.utah.edu - thanks!
Also, merge UCB and Utah copyright texts back into one, as they
originally were.

Extra verification by snj@.

branches: 1.21.78; 1.21.84; 1.21.86;
Conversion to clock_ymdhms wasn't complete: the match routine was calling
ugettod() with a NULL pointer to test if the clock was present. That
argument was changed to a struct clock_ymdhms pointer and is no longer
optional. Change to pass the address of a local structure when probing
for the clock.

branches: 1.20.2;
Convert a2kbbc and a3kbbc to newer clock_ymdhms convenience routines in
kern_todr.

Correct some error returns for gettod() and settod() left over from the
pre-todr code, and use actual E* return codes for any error return.

branches: 1.18.2;
Switch amiga to MI todr.

branches: 1.17.4; 1.17.8;
merge ktrace-lwp.

branches: 1.16.2;
Fix a ton of const/volatile issues shown with new warning flags

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

branches: 1.14.6;
Use CFATTACH_DECL().

Declare all cfattach structures const.

add __KERNEL_RCSID as suggested by Luke Mewburn

- ANSIfy
- remove some trailing spaces/tabs
- minor style nits

branches: 1.10.8; 1.10.12;
Kill a couple of unnecessary cf_unit (ab)uses.

Write part of the y2k fix.
This is not strictly necessary, as
- at least for the Ricoh chip in the A3000 and A4000, as those chips' Y10
registers happily continue to count up from 0xA if manually incremented
past 0x9.
- the Amiga ROMs and "setclock" commands seem to interpret 0xA 0x? like
200?, etc.

However,
- the Amiga setclock writes the modulo 10 value into the chips
- the chip docs of both chips, including the Y2K information of their
manufacturers, only refer to the range 0-9
- the chips increment from 9 to 0

So we better conform to this, to avoid unpleasant surprises.

*sigh*
Y2000-patch for A2000, A3000 and A4000 battery backed clock modules,
mostly by Adam Ciarcinski.

branches: 1.7.2; 1.7.8;
Dont write through a zero pointer (when in probe mode of a2kugettod()).

Use the 1/256s-resolution when reading the DraCo battery backed clock

Adjust for changes to config.

zbus.c

Fix a complaint by Eric Delcamp on port-amiga... looks like Thorsten Fruehauf
didn't find all occurences of unprotected is_draco(), and I didn't look hard
enough, either, when fixing.

a2kbbc_match(): check unit explicitly against 0. Minor KNF.

Make Amiga battery clocks autoconfiguration devices, so that they can be
left out of specialized configurations.