netdev: make net_device_ops const

More drivers where net_device_ops should be const.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/tile/tilepro.c b/drivers/net/ethernet/tile/tilepro.c
index 6b75063..d9951af 100644
--- a/drivers/net/ethernet/tile/tilepro.c
+++ b/drivers/net/ethernet/tile/tilepro.c
@@ -2260,8 +2260,7 @@
 	return 0;
 }
 
-
-static struct net_device_ops tile_net_ops = {
+static const struct net_device_ops tile_net_ops = {
 	.ndo_open = tile_net_open,
 	.ndo_stop = tile_net_stop,
 	.ndo_start_xmit = tile_net_tx,