ixgbe: Implement FCoE Rx side large receive offload feature to 82599

This patch implements the FCoE Rx side offload feature in ixgbe_main.c
to 82599 using the Rx offload infrastructure code added in the previous
patch. The large receive offload by Direct Data Placement (DDP) for
FCoE is achieved by implementing the ndo_fcoe_ddp_setup and ndo_fcoe_ddp_done
in net_device_ops via netdev. It is up to the ULD, i.e., fcoe and libfc
to query and setup large receive offload accordingly through the corresponding
netdev upon creating fcoe instances.

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>