V4L/DVB (3105): Remove AUDC_CONFIG_PINNACLE horror, fix mt20xx radio support.

- Remove AUDC_CONFIG_PINNACLE horror. This also fixes radio support
for mt20xx tuners.

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