drm/bridge: cdns-mhdp8546: clear the EDID property on failures

If EDID read fails, clear the EDID property.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/a754d9f90fe2addb9d90f9638e3d53dce87bdabc.1706038510.git.jani.nikula@intel.com

drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c

@@ -1524,12 +1524,14 @@ static int cdns_mhdp_get_modes(struct drm_connector *connector)
 		return 0;
 
 	drm_edid = cdns_mhdp_edid_read(mhdp, connector);
+
+	drm_edid_connector_update(connector, drm_edid);
+
 	if (!drm_edid) {
 		dev_err(mhdp->dev, "Failed to read EDID\n");
 		return 0;
 	}
 
-	drm_edid_connector_update(connector, drm_edid);
 	num_modes = drm_edid_connector_add_modes(connector);
 	drm_edid_free(drm_edid);