drm/imx: don't skip DP channel disable for background plane

[ Upstream commit 7bcde275eb1d0ac8793c77c7e666a886eb16633d ]

In order to make sure that the plane color space gets reset correctly.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

drivers/gpu/drm/imx/ipuv3-crtc.c

@@ -78,7 +78,7 @@ static void ipu_crtc_disable_planes(struct ipu_crtc *ipu_crtc,
 	if (disable_partial)
 		ipu_plane_disable(ipu_crtc->plane[1], true);
 	if (disable_full)
-		ipu_plane_disable(ipu_crtc->plane[0], false);
+		ipu_plane_disable(ipu_crtc->plane[0], true);
 }
 
 static void ipu_crtc_atomic_disable(struct drm_crtc *crtc,