media: rcar-vin: Make use of V4L2_CAP_IO_MC

Set the V4L2_CAP_IO_MC capability flag and remove the driver specific
vidioc_enum_input, vidioc_g_input and vidioc_s_input callbacks for the
media controller enabled part of the driver. Also add support mbus_code
filtering for format enumeration.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-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>