V4L/DVB (11638): gspca - m5602-ov7660: Make an educated guess on the proper hsync/vsync

Based on how the ov9650 is configured, make an educated guess on the hsync/vsync setup for the ov7660

Signed-off-by: Erik Andrén <erik.andren@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>