iwlwifi: mvm: always send power table command

The driver distinguishes between power management and device's power
down enablement. Power management enablement depends both on driver's
module power parameters and mac80211 decision. The device's power down
depends only on driver's module power parameters. Change the driver to
always send Power Table command to enable or disable both power
management and device's power down.

Signed-off-by: Alexander Bondar <alexander.bondar@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>