ixgbe: add support for 82599 based Express Module X520-P2

This patch will add the device ID for the 82599-based Ethernet
Express Module X520-P2 SFI card.

Signed-off-by: Don Skidmore <donald.c.skidmore@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>