HDA Codec driver
Clean up and fix ALC-codec support code.

The last addition of bound volume is fixed now to handle correctly
the bound 'mute switches'.  The analog loopback should work better.
The init verbs are fixed together with this change.

The numbers are replaced with macros for better readability.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>