IBM-EMAC: 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/ibm/emac/mal.c b/drivers/net/ethernet/ibm/emac/mal.c
index dddaab1..fdb5cdb 100644
--- a/drivers/net/ethernet/ibm/emac/mal.c
+++ b/drivers/net/ethernet/ibm/emac/mal.c
@@ -753,7 +753,7 @@
 	return 0;
 }
 
-static struct of_device_id mal_platform_match[] =
+static const struct of_device_id mal_platform_match[] =
 {
 	{
 		.compatible	= "ibm,mcmal",