iwlwifi: disable WoWLAN if !CONFIG_PM_SLEEP

iwlwifi: disable WoWLAN if !CONFIG_PM_SLEEP

commit fcb6ff5e2cb83e1de10631f6621f45ca3401bf61 upstream.

If CONFIG_PM_SLEEP is disabled, then iwlwifi doesn't
support suspend/resume handlers and thus mac80211
(correctly) refuses advertising WoWLAN. Disable
WoWLAN in the driver in this case.

Reported-by: Sebastian Kemper <sebastian_ml@gmx.net>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
[bwh: Backported to 3.2: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>