This makes the soc-camera interface for V4L2 subdevices thinner yet. Handle
gain and exposure internally in each driver just like all other controls.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>