RFC: massive snd_hda driver update to better conform UAA specification

[George Hartzell]

I have a Mac Pro running -STABLE amd64.

I applied the -STABLE version of the patch to a tree that I csup'ed
yesterday without any trouble.

Previously I had to set hint.pcm.0.config="gpio1" in
/boot/device.hints to get either of the jacks work properly.  Sound
worked but was very, very loud, I had to set the volume down around 2%
for it to be listenable.

With the new driver sound still works, but now it's very quiet.
Turning the volumes all the way up in mixer and on the gnome desktop
and in rhythmbox just gives me something listenable.

With the new driver I have several pcm devices and several dsp and
mixer devices in /dev that I don't think used to be there.
pcm[01234], /dev/dsp{0.0,1.0,2.0,3.0} and /dev/mixer[0123].

I've put sndstat output at:

   http://shrimp.alerce.com/macpro/sndstat.out

and verbose dmesg is at:

   http://shrimp.alerce.com/macpro/dmesg-verbose.out

Any suggestions about how I can get the volume up to a normal range?

Thanks,

g.