V4L/DVB (4702): Fix: set antenna input for DVB-T for Asus P7131 Dual hybrid

This patch forces the correct antenna input input in DVB-T
mode for this card.

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>