atl1c: remove PHY polling from atl1c_change_mtu

PHY polling code for FPGA is considered in every MDIO R/W API.
no need to add additional code to atl1c_change_mtu.

Signed-off-by: xiong <xiong@qca.qualcomm.com>
Tested-by: David Liu <dwliu@qca.qaulcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/atheros/atl1c/atl1c_main.c

@@ -553,14 +553,6 @@ static int atl1c_change_mtu(struct net_device *netdev, int new_mtu)
 		netdev_update_features(netdev);
 		atl1c_up(adapter);
 		clear_bit(__AT_RESETTING, &adapter->flags);
-		if (adapter->hw.ctrl_flags & ATL1C_FPGA_VERSION) {
-			u32 phy_data;
-
-			AT_READ_REG(&adapter->hw, 0x1414, &phy_data);
-			phy_data |= 0x10000000;
-			AT_WRITE_REG(&adapter->hw, 0x1414, phy_data);
-		}
-
 	}
 	return 0;
 }