This notifies pipeline handlers when a camera is released, in case they want to free any resources or memory buffers. Signed-off-by: David Plowman <david.plowman@raspberrypi.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Naushir Patuck <naush@raspberrypi.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>