Use flags the device exposes for UVC controls.
This allows the device to define which property flags are set.

Since some cameras offer auto-adjustments for properties (e.g. auto-gain),
the values of other properties (e.g. gain) can change in the camera.
Examining the flags ensures that the driver is aware of such properties.
Signed-off-by: Edgar Thier <info@edgarthier.net>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>