ixgbe: Add support for the net_device_ops.ndo_fcoe_enable/disable to 82599

This adds support to the net_device_ops.ndo_fcoe_enable/disable for 82599. This
consequently allows us to dynamically turn FCoE offload feature on or off
upon incoming calls to ndo_fcoe_enable/disable. When this happens, FCoE offload
features are enabled/disabled accordingly, and this is regardless of whether
DCB being turned on or not.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Acked-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ixgbe/ixgbe.h b/drivers/net/ixgbe/ixgbe.h
index c983c89..daed0ac 100644
--- a/drivers/net/ixgbe/ixgbe.h
+++ b/drivers/net/ixgbe/ixgbe.h
@@ -450,6 +450,8 @@
 extern int ixgbe_fcoe_ddp_get(struct net_device *netdev, u16 xid,
                               struct scatterlist *sgl, unsigned int sgc);
 extern int ixgbe_fcoe_ddp_put(struct net_device *netdev, u16 xid);
+extern int ixgbe_fcoe_enable(struct net_device *netdev);
+extern int ixgbe_fcoe_disable(struct net_device *netdev);
 #endif /* IXGBE_FCOE */
 
 #endif /* _IXGBE_H_ */