Reset rotation property to 0.

v2: Resetting after disabling the plane
Signed-off-by: NSonika Jindal <sonika.jindal@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>