V4L/DVB (8835): gspca: Same pixfmt as the sn9c102 driver and raw Bayer added in sonixb.

1) Lower the hstart setting for all sensor by 1 so that we generate
   (compressed) BGGR data just like sn9c102 does (instead of GBRG data)
2) Add support for raw bayer output in the lowest resolutions (not enough
   bandwidth for higher resolutions), this should work with all sensors but
   to be sure only enable it for sensors where it has been tested.

Signed-off-by: Hans de Goede <j.w.r.degoede@hhs.nl>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>