iwlwifi: mvm: configure power management in D3

Configure power management in the D3 firmware by sending
the power table command to it when suspending; this uses
some values that are more suitable to a low power state.

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>