drm/nouveau: set encoder for lvds

fixes oops in nouveau_connector_get_modes with nv_encoder is NULL

Signed-off-by: Albert Damen <albrt@gmx.net>
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_connector.c

@@ -365,6 +365,7 @@ out:
 #endif
 
 	drm_mode_connector_update_edid_property(connector, nv_connector->edid);
+	nouveau_connector_set_encoder(connector, nv_encoder);
 	return status;
 }