Return controls::FrameDuration through the per-frame Request metadata. The frame duration is obtained by either the value in DelayedControls, or (preferably) the value parsed from the embedded data buffer. Signed-off-by: Naushir Patuck <naush@raspberrypi.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: David Plowman <david.plowman@raspberrypi.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>