can: flexcan: make declaration of devtype_data const

This patch changes the declaration of the devtype data to const.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 44a5aae..84e465a9 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -268,17 +268,17 @@ struct flexcan_priv {
 	struct regulator *reg_xceiver;
 };
 
-static struct flexcan_devtype_data fsl_p1010_devtype_data = {
+static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_BROKEN_ERR_STATE,
 };
 
-static struct flexcan_devtype_data fsl_imx28_devtype_data;
+static const struct flexcan_devtype_data fsl_imx28_devtype_data;
 
-static struct flexcan_devtype_data fsl_imx6q_devtype_data = {
+static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG,
 };
 
-static struct flexcan_devtype_data fsl_vf610_devtype_data = {
+static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_DISABLE_MECR,
 };