[ALSA] WM97xx AC97 codec controls

AC97 Codec
o Enhanced current WM97xx support to provide additional controls and
  use the kcontrol suffix naming convention.
o Added AC97_HAS_NO_MIC, AC97_HAS_NO_TONE and AC97_HAS_NO_STD_PCM.
o Cleaned up WM97xx related comments.
o Removed some wm9713 double mono controls and replaced with stereo
  controls.

Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>