igb: Add full support for 82580 devices

This patch makes use of the 82580 PHY and MAC support added and adds a set
of supported device IDs for said hardware.

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>