V4L/DVB (3246): Use VIDIOC_S_AUDIO instead of AUDC_SET_INPUT in cs53l32a

- Replace AUDC_SET_INPUT with VIDIOC_S_AUDIO.
- Added V4L2_CID_AUDIO_MUTE.
- Minimum volume is -96 dB, not -90.
- Show volume in VIDIOC_LOG_STATUS.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>