V4L/DVB (4962): Add the Composite over S-Video input on the Asus P7131 Dual

This makes a second CVBS input available.

Signed-off-by: Hermann Pitton <hermann-pitton@arcor.de>
Signed-off-by: Hartmut Hackmann <hartmut.hackmann@t-online.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>