ar71xx: ag71xx: add missing register writes

These are added in ath79, but were not backported here

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>

target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c

@@ -1274,6 +1274,9 @@ static int ag71xx_change_mtu(struct net_device *dev, int new_mtu)
 		return -EBUSY;
 
 	dev->mtu = new_mtu;
+	ag71xx_wr(ag, AG71XX_REG_MAC_MFL,
+		  ag71xx_max_frame_len(dev->mtu));
+
 	return 0;
 }
 
@@ -1413,6 +1416,8 @@ static int ag71xx_probe(struct platform_device *pdev)
 
 	ag71xx_dump_regs(ag);
 
+	ag71xx_wr(ag, AG71XX_REG_MAC_CFG1, 0);
+
 	ag71xx_hw_init(ag);
 
 	ag71xx_dump_regs(ag);