drm: rcar-du: Constify node argument to rcar_du_lvds_connector_init()

The node passed as a pointer to the rcar_du_lvds_connector_init()
function is never modified, make it const.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c

@@ -79,7 +79,7 @@ static const struct drm_connector_funcs connector_funcs = {
 
 int rcar_du_lvds_connector_init(struct rcar_du_device *rcdu,
 				struct rcar_du_encoder *renc,
-				/* TODO const */ struct device_node *np)
+				const struct device_node *np)
 {
 	struct drm_encoder *encoder = rcar_encoder_to_drm_encoder(renc);
 	struct rcar_du_lvds_connector *lvdscon;

drivers/gpu/drm/rcar-du/rcar_du_lvdscon.h

@@ -19,6 +19,6 @@ struct rcar_du_encoder;
 
 int rcar_du_lvds_connector_init(struct rcar_du_device *rcdu,
 				struct rcar_du_encoder *renc,
-				struct device_node *np);
+				const struct device_node *np);
 
 #endif /* __RCAR_DU_LVDSCON_H__ */