V4L/DVB (5481): Fix audio input for AverTv Go 007

Fix audio input source for capturing(playing) audio on AverTv Go 007 cards.

Signed-off-by: Damian Minkov <damencho@damencho.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>