drm/imx: imx-ldb: Accept drm_of_find_panel_or_bridge failure

Not having an endpoint bound in DT should not cause a failure here,
there are fallbacks. So explicitly accept a missing endpoint.

This behavior change was introduced by refactoring in drm_of parsing
code and it should not require dts changes.

In particular this fixes imx6qdl-sabreauto boards.

Link: https://lists.freedesktop.org/archives/dri-devel/2017-May/141233.html
Fixes: ebc944613567 ("drm: convert drivers to use drm_of_find_panel_or_bridge")
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/imx/imx-ldb.c

@@ -673,7 +673,7 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
 		ret = drm_of_find_panel_or_bridge(child,
 						  imx_ldb->lvds_mux ? 4 : 2, 0,
 						  &channel->panel, &channel->bridge);
-		if (ret)
+		if (ret && ret != -ENODEV)
 			return ret;
 
 		/* panel ddc only if there is no bridge */