RFC: massive snd_hda driver update to better conform UAA specification

[George Hartzell]

George Hartzell writes:
 > 
 > 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.

Alexander pointed out that with the new driver the name of the hint
has changed, and that that I should be using

   hint.hdac.0.config="gpio1"

This gives me completely reasonable volume control, which I didn't
have with the older driver.

I still don't have automatic jack sensing though.

Thanks!

g.