iwlagn: send simple LQ command for WoWLAN

For some reason, WoWLAN doesn't always seem to
be happy with more advanced LQ commands. Since
we don't need them as we're not going to send
a lot of data, simply program the station with
the very simple default LQ command.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>