[media] saa7134: use V4L2_IN_ST_NO_SIGNAL instead of NO_SYNC

NO_SYNC was meant for DVB and shouldn't be used anymore.

In this case NO_SIGNAL is a good alternative.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>