This is especially important during shutdown because a child interface
of lagg with WOL enabled will not enable WOL at interface shutdown and
thus no WOL to wake up the device (and machine).
PR: 158734, 109980
Reported by: Antonio Huete Jimenez <tuxillo at quantumachine.net>
Marat N.Afanasyev <marat at zealot.ksu.ru>
reviewed by: kp
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D26797
bd0e0447cb