net: phy: 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>

drivers/net/phy/mdio-mux-mmioreg.c

@@ -145,7 +145,7 @@ static int mdio_mux_mmioreg_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static struct of_device_id mdio_mux_mmioreg_match[] = {
+static const struct of_device_id mdio_mux_mmioreg_match[] = {
 	{
 		.compatible = "mdio-mux-mmioreg",
 	},