V4L/DVB (12522): sh-mobile-ceu-camera: implement host-side cropping

V4L/DVB (12522): sh-mobile-ceu-camera: implement host-side cropping

Not all video capture devices can configure arbitrary cropping, whereas the
CEU module on SuperH CPUs can crop with pixel precision. However, we want to
use camera cropping if possible to save bandwidth and increase the frame-rate.
This patch verifies whether the camera managed to crop exactly the requested
rectangle, and if not, uses host-side cropping. To be able to crop on CEU we
have to preserve camera rectangle too, for which the host_priv member in
struct soc_camera_device is used. We now allocate memory dynamically, thus we
have to use the .put_formats() method from struct soc_camera_host_ops to free
it.

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