iwlwifi: mvm: set immediate apply time bit in time events

Newer firmware support a new bit in the policy  that allows
to request to apply the time event immediately. Add this bit
without removing the workarounds we used until now to support
older firmares.

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