net/fsl: constify of_device_id array

of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/fec_mpc52xx.c b/drivers/net/ethernet/freescale/fec_mpc52xx.c
index f495796..afe7f39 100644
--- a/drivers/net/ethernet/freescale/fec_mpc52xx.c
+++ b/drivers/net/ethernet/freescale/fec_mpc52xx.c
@@ -1057,7 +1057,7 @@
 }
 #endif
 
-static struct of_device_id mpc52xx_fec_match[] = {
+static const struct of_device_id mpc52xx_fec_match[] = {
 	{ .compatible = "fsl,mpc5200b-fec", },
 	{ .compatible = "fsl,mpc5200-fec", },
 	{ .compatible = "mpc5200-fec", },