iwlwifi: mei: clear the sap data header before sending

The SAP data header has some fields that are marked as reserved
but are actually in use by CSME. Clear those fields before sending
the data to avoid having random values in those fields.

Cc: stable@vger.kernel.org
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20220517120045.8dd3423cf683.I02976028eaa6aab395cb2e701fa7127212762eb7@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>