igb: Fixed Wake On LAN support

This patch fixes Wake on LAN being reported as supported on some Ethernet
ports, in contrary to Hardware capability.

Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>