can: rcar_can: add .ndo_change_mtu function

Use common can_change_mtu function.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/rcar_can.c b/drivers/net/can/rcar_can.c
index 1abe133..9718248 100644
--- a/drivers/net/can/rcar_can.c
+++ b/drivers/net/can/rcar_can.c
@@ -628,6 +628,7 @@
 	.ndo_open = rcar_can_open,
 	.ndo_stop = rcar_can_close,
 	.ndo_start_xmit = rcar_can_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
 };
 
 static void rcar_can_rx_pkt(struct rcar_can_priv *priv)