[media] V4L: Add capability flags for memory-to-memory devices

This patch adds new V4L2_CAP_VIDEO_M2M and V4L2_CAP_VIDEO_M2M_MPLANE
capability flags that are intended to be used for memory-to-memory (M2M)
devices, instead of ORed V4L2_CAP_VIDEO_CAPTURE and V4L2_CAP_VIDEO_OUTPUT.

V4L2_CAP_VIDEO_M2M flag is added at the drivers, CAPTURE and OUTPUT
capability flags are left untouched and will be removed in future,
after a transition period required for existing applications to be
adapted to check only for V4L2_CAP_VIDEO_M2M.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Kamil Debski <k.debski@samsung.com>
Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>