ixgbe: enable SCTP checksum offload for X540

X540 supports SCTP checksum offload so enable it.  It was overlooked when X540
support was initially added to the driver.
Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Evan Swanson <evan.swanson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ixgbe/ixgbe_main.c

@@ -7361,8 +7361,14 @@ static int __devinit ixgbe_probe(struct pci_dev *pdev,
 	netdev->features |= NETIF_F_TSO6;
 	netdev->features |= NETIF_F_GRO;
 
-	if (adapter->hw.mac.type == ixgbe_mac_82599EB)
+	switch (adapter->hw.mac.type) {
+	case ixgbe_mac_82599EB:
+	case ixgbe_mac_X540:
 		netdev->features |= NETIF_F_SCTP_CSUM;
+		break;
+	default:
+		break;
+	}
 
 	netdev->vlan_features |= NETIF_F_TSO;
 	netdev->vlan_features |= NETIF_F_TSO6;