ixgbe: Enable FCoE offload when DCB is enabled for 82599

Currently, FCoE offload feature is turned on when the kernel config has
CONFIG_FCOE or CONFIG_FCOE_MODULE set. However, we really want to turn
FCoE offload on when there is FCoE traffic passing and turn it off when
it's just LAN traffic. Since FCoE depends on a lossless network provided
by DCB, this allows us to have FCoE turned on/off when user turns on DCB
using dcbtool.

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 cd22323..1b12c7b 100644
--- a/drivers/net/ixgbe/ixgbe.h
+++ b/drivers/net/ixgbe/ixgbe.h
@@ -327,6 +327,7 @@
 #define IXGBE_FLAG_IN_SFP_MOD_TASK              (u32)(1 << 25)
 #define IXGBE_FLAG_FDIR_HASH_CAPABLE            (u32)(1 << 26)
 #define IXGBE_FLAG_FDIR_PERFECT_CAPABLE         (u32)(1 << 27)
+#define IXGBE_FLAG_FCOE_CAPABLE                 (u32)(1 << 28)
 #define IXGBE_FLAG_FCOE_ENABLED                 (u32)(1 << 29)
 
 	u32 flags2;