Store the frame length into the DeviceStatus struct. The value is extracted from embedded data when available, or calculated from the VBLANK value passed from DelayedControls otherwise. Update imx477 and imx219 CamHelper classes to extract the frame length from the embedded data buffer. Signed-off-by: Naushir Patuck <naush@raspberrypi.com> Reviewed-by: David Plowman <david.plowman@raspberrypi.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>