ALSA: hda - Fix / clean up IDT92HD83xxx codec parser

A few improvements for IDT 92HD83xxx codec pareser:
- Remove unused / deprecated mixer-amp controls
- Handle d-mics as normal inputs since this codec has no separate
  MUXes for analog and digital
- Don't create duplicated controls for capture volumes with Mux
  capture volumes

Signed-off-by: Takashi Iwai <tiwai@suse.de>