V4L/DVB (12524): soc-camera: S_CROP V4L2 API compliance fix

V4L2 API mandates, that drivers do not update the argument of the S_CROP
ioctl() with the actual geometry. Comply.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>