drivers/net: const-ify ethtool_ops declarations

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/arm/etherh.c b/drivers/net/arm/etherh.c
index d52deb8..4ae9897 100644
--- a/drivers/net/arm/etherh.c
+++ b/drivers/net/arm/etherh.c
@@ -626,7 +626,7 @@
 	return 0;
 }
 
-static struct ethtool_ops etherh_ethtool_ops = {
+static const struct ethtool_ops etherh_ethtool_ops = {
 	.get_settings	= etherh_get_settings,
 	.set_settings	= etherh_set_settings,
 	.get_drvinfo	= etherh_get_drvinfo,