Merge thorpej-cfargs2.

Merge thorpej-cfargs branch:

Simplify and make extensible the config_search() / config_found() /
config_attach() interfaces: rather than having different variants for
which arguments you want pass a

Merge thorpej-cfargs branch:

Simplify and make extensible the config_search() / config_found() /
config_attach() interfaces: rather than having different variants for
which arguments you want pass along, just have a single call that
takes a variadic list of tag-value arguments.

Adjust all call sites:
- Simplify wherever possible; don't pass along arguments that aren't
actually needed.
- Don't be explicit about what interface attribute is attaching if
the device only has one. (More simplification.)
- Add a config_probe() function to be used in indirect configuiration
situations, making is visibly easier to see when indirect config is
in play, and allowing for future change in semantics. (As of now,
this is just a wrapper around config_match(), but that is an
implementation detail.)

Remove unnecessary or redundant interface attributes where they're not
needed.

There are currently 5 "cfargs" defined:
- CFARG_SUBMATCH (submatch function for direct config)
- CFARG_SEARCH (search function for indirect config)
- CFARG_IATTR (interface attribte)
- CFARG_LOCATORS (locators array)
- CFARG_DEVHANDLE (devhandle_t - wraps OFW, ACPI, etc. handles)

...and a sentinel value CFARG_EOL.

Add some extra sanity checking to ensure that interface attributes
aren't ambiguous.

Use CFARG_DEVHANDLE in MI FDT, OFW, and ACPI code, and macppc and shark
ports to associate those device handles with device_t instance. This
will trickle trough to more places over time (need back-end for pre-OFW
Sun OBP; any others?).

show more ...

Kill some more extern struct cfdriver declarations.

Down with externs in .c!

spl leak, found by Mootja

fix unused variable warning

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

struct device * -> device_t, no functional changes intended.

struct cfdata * -> cfdata_t, no functional changes intended.

Register with pmf(9), tell it we don't need anything.

Switch apmdev to use apm(4) structures from dev/apm/apmvar.h.
Add batteryid argument to aa_get_powstat method implementations.

Fix battery_state vs. battery_flags confusion.
Fill all fields of struct apm_power_info in hpcapm_get_powstat.

machine/{bus,cpu,intr}.h -> sys/{bus,cpu,intr}.h

__unused removal on arguments; approved by core.

-Wextra fixes

Remove (the default) #define XXXDEBUG and add the options to the relevant
files.xxx file.

Improve some debug texts.

Fix a pasto: save CONFIG_HOOK_PMEVENT_AC hook in the correct variable.
From Adam Wysocki on port-hpcsh@.

Use device_private().

Remove the include <machine/autoconf.h>, it is a) not needed any more and
b) not available on all hpc ports.

Rework hpcapm(4) attachment definition so it is not required to attach at
mainbus, and convert its two users, hpcsh and hpcmips, to that.

Many thanks to Valeriy Ushakov and Ben Collver for testing.

merge ktrace-lwp.

Get AC/battery state via config_hook_call if hooks are registered.

nuke trailing whitespace

hpcmips independent part are moved to sys/dev/hpc/