ixgbe: Add support for 82599 alternative WWNN/WWPN prefix

The 82599 EEPROM supports alternative prefix for World Wide Node Name
(WWNN) and World Wide Port Name (WWPN). The prefixes can be used together
with the SAN MAC address to form the WWNN and WWPN, which can be used by
upper layer drivers such as Fiber Channel over Ethernet (FCoE).

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>