ixgbe: Fix WoL functionality for 82599 KX4 devices

The current code writes the PME enabled bit in PCI config space which is
wrong.  This was needed for pre-release hardware, and was not removed from
the driver.  Also, we need to clear the WUS (wake up status) after we
resume.  Otherwise we can't wake for the same event again since it's still
asserted in the hardware.  Plus, the multicast lists were being written
improperly, causing multicast WoL to fail.

Signed-off-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>