can: mpc5xxx_can: make data used as *of_device_id.data const

Since of_device_id.data is declared as a pointer to const data a few
more consts can be added in this driver.

[ukl: split Arnd's patch by driver]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/net/can/mscan/mpc5xxx_can.c

@@ -380,12 +380,12 @@ static int mpc5xxx_can_resume(struct platform_device *ofdev)
 }
 #endif
 
-static struct mpc5xxx_can_data __devinitdata mpc5200_can_data = {
+static const struct mpc5xxx_can_data __devinitdata mpc5200_can_data = {
 	.type = MSCAN_TYPE_MPC5200,
 	.get_clock = mpc52xx_can_get_clock,
 };
 
-static struct mpc5xxx_can_data __devinitdata mpc5121_can_data = {
+static const struct mpc5xxx_can_data __devinitdata mpc5121_can_data = {
 	.type = MSCAN_TYPE_MPC5121,
 	.get_clock = mpc512x_can_get_clock,
 };