In order for igb to support MDI setting support via
ethtool this code is needed to allow setting the MDI state
via software.

This is in regards to the related ethtool patch
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Aaron Brown aaron.f.brown@intel.com
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>