Ensure the side-by-side (half) flag is added to any existing flags when
adding modes from 3D_Structure_ALL.
Signed-off-by: NThomas Wood <thomas.wood@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>