V4L/DVB (9543): gspca: Adjust autoexpo values for cams with a vga sensor in sonixb.

- This patch makes sonixb.c strife to different values during autoexposure
  for sif versus vga sensors.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>