[media] V4L: pxa_camera: convert to the new mbus-config subdev operations

Switch from soc-camera specific .{query,set}_bus_param() to V4L2
subdevice .[gs]_mbus_config() operations.

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