igb: add support for 82576 mezzanine card

This patch adds support for a new 82576 mezzanine adapter.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/net/igb/e1000_82575.c
Simple merge

diff --cc drivers/net/igb/e1000_hw.h
Simple merge

diff --cc drivers/net/igb/igb_main.c
Simple merge