When the RGB means are too small, gains and color temperature can't be
meaningfully calculated. Freeze the AWB in that case, using the
previously calculated values.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>