media: staging/intel-ipu3: Make use of V4L2_CAP_IO_MC

Set the V4L2_CAP_IO_MC capability flag and remove the driver specific
vidioc_enum_{input,output}, vidioc_g_{input,output} and
vidioc_s_{input,output} callbacks.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>