net: via-rhine: 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 <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/via/via-rhine.c

···
  * The .data field is currently only used to store quirks
  */
 static u32 vt8500_quirks = rqWOL | rqForceReset | rq6patterns;
-static struct of_device_id rhine_of_tbl[] = {
+static const struct of_device_id rhine_of_tbl[] = {
 	{ .compatible = "via,vt8500-rhine", .data = &vt8500_quirks },
 	{ }	/* terminate list */
 };