Remove unnecessary include of <sys/malloc.h>.

Merge isaki-audio2 branch, the overhaul of audio subsystem.
- Interrupt-oriented system rather than thread-oriented.
- Improve stability, quality and performance.
- Split playback and record cleanly. Improve halfduplex support.
- Many bugs are fixed including deadlocks, resource leaks, abuses, etc.
- Simplify audio filter mechanism. The encoding/channels/frequency
conversions are completely handled in the upper layer. So the hard-
ware driver only converts its hardware encoding (if necessary).
- audio_hw_if changes:
- Obsoletes query_encoding and add query_format instead.
- Obsoletes set_params and add set_format instead.
- Remove drain, setfd, mappage.
- The call sequences are changed.
- ioctl AUDIO_GETFD/SETFD, AUDIO_GETCHAN/SETCHAN are obsoleted.
- ioctl AUDIO_{QUERY,GET,SET}FORMAT are introduced.
- cleanup config attributes: au*conv and mulaw.
- All hardware drivers should follow it (I've done as much as possible).

Some file paths are changed:
- dev/audio.c -> dev/audio/audio.c (rewritten)
- dev/audiovar.h -> dev/audio/audiovar.h
- dev/audio_dai.h -> dev/audio/audio_dai.h
- dev/audio_if.h -> dev/audio/audio_if.h
- dev/audiobell.c -> dev/audio/audiobell.c
- dev/audiobellvar.h -> dev/audio/audiobellvar.h
- dev/mulaw.[ch] -> dev/audio/mulaw.[ch] + dev/audio/alaw.c

branches: 1.15.40; 1.15.44;
Tidy up a little, the way that midi attachment code works

- change midi_attach() to omit the 'parent' arg (there are
only two callers of this and it is not used)

- change midisyn_attach() to midisyn_init(), so not needing a midi_softc,
and fix the midi_pcppi driver to set hw_if and hw_hdl directly in
its midi_softc before calling midi_attach()

- add a device_t to opl_softc structure, change opl drivers to store
the device 'self' in opl_softc and fix opl_attach() to use this
opl_softc->dev field directly rather than a field in an otherwise
unused midi_softc

- remove unnecessary midi_softc from opl and cms drivers (child device
provides that)

reviewed by mrg

Initialize the opl softc lock pointer to the parent's interrupt lock.
Briefly tested only on wss@isapnp.

branches: 1.13.34; 1.13.38;
Remove clause 3 and 4 from TNF licenses

branches: 1.12.2; 1.12.4;
Split device_t and softc for opl(4). That should have been done along with
midi(4), because opl_softc embed a midi_softc.
Fixes PR#38242 by Onno van der Linden.

branches: 1.11.12; 1.11.16;
machine/{bus,cpu,intr}.h -> sys/{bus,cpu,intr}.h

branches: 1.10.8; 1.10.22; 1.10.24; 1.10.28;
__unused removal on arguments; approved by core.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

branches: 1.8.6; 1.8.8;
stack police: Introduce an opl_match function that uses malloc instead of
allocating ~2K of softc on the stack.

branches: 1.7.4; 1.7.8; 1.7.14;
merge ktrace-lwp.

branches: 1.6.6;
de-__P

branches: 1.5.6; 1.5.14; 1.5.16;
Fix sizeof and whitespace bug from the script I'm using to do the
CFATTACH_DECL conversion. (Grumble.)

Use CFATTACH_DECL().

Declare all cfattach structures const.

add RCSID

branches: 1.1.14; 1.1.16;
Implement opl at wss.