Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Rearrange this code slightly to pass softcs around instead of device_t,
solving a possible panic when snd_ai2s is loaded at boot time. Also change
the device setup to indicate to the pcm layer that the device is MPSAFE.

Submitted by: Marco Trillo
Suggestions by: Ariff Abdullah

Change the way our softc is stored to use the devinfo facility provided by pcm
instead of the regular device softc interface. This brings the AOA driver in
line with the other pcm drivers.

Requested by: ariff

Add support for the I2S and davbus audio controllers found in Apple PowerPC
hardware.

Submitted by: Marco Trillo