ixgbe: only allow WOL for 82599 KX4 NIC

All NICs were reporting WOL support when only the KX4 NIC is capable of
supporting WOL.  This patch adds a function to check for and exclude all
non-WOL capable nics from enabling WOL in ethtool.

Signed-off-by: Alexander Duyck <alexander.h.duyck@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>