MIPS: Loongson1B: Update stmmac_mdio_bus_data

Update stmmac_mdio_bus_data accordingly due to the upstream change.
Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
Patchwork: http://patchwork.linux-mips.org/patch/4433Signed-off-by: John Crispin <blogic@openwrt.org>

arch/mips/loongson1/common/platform.c

@@ -71,7 +71,6 @@ static struct resource ls1x_eth0_resources[] = {
 };
 
 static struct stmmac_mdio_bus_data ls1x_mdio_bus_data = {
-	.bus_id		= 0,
 	.phy_mask	= 0,
 };