iwlwifi: mvm: sync the iwl_mvm_session_prot_notif layout

The firmware API has changed a little bit but this change
has no impact on the flow and is backward compatible.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>