media: rockchip: rga: add feature flags

media: rockchip: rga: add feature flags

In preparation to the RGA3 addition add feature flags, which can limit
the exposed feature set of the video device, like rotating or selection
support. This is necessary as the RGA3 doesn't initially implement the
full feature set currently exposed by the driver.

Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Sven Püschel <s.pueschel@pengutronix.de>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>