V4L/DVB (13998): gscpa_ov519: Fix 320x240 on ov519 + ov7648

Differentiate between ov7640 and ov7648 and handle the ov7648 320x240
on the ov519 bridge specially to fix r and b being swapped.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>