SOUND CONTROL: exclude all that i dont need to control. + more.

*Set default MIC gain.
*Add descriptions for controls.
*Remove PA lock from wcd9320.c, LG dont need it.
PA control work OK, and must be reset to default when no sound.
then it's will be back to tuned value on playback.
Revert "ASoC: wcd9320: Use class AB headphone path for high-res formats"

This reverts commit 5e45b71bda8c358c2a82c3e45ff0c519c0299605.

For LG. it's best to use class AB always ON. then sound is clear!
no hissing on low end headphones/headsets.
Revert "Revert "snd: wcd9320: Enable class AB mode always""

This reverts commit a82624e7cc2a2a6e1637e6d068470bc4647da21a.