iwlwifi: mvm: add support for new FTM fw API

The FTM new API uses API TLV bit 15. The driver mistakenly uses
this bit for beacon filter API, although no TLV was assigned for
the beacon filter API. For now, make beacon filter use bit 16
instead (not set by the fw anyway). Once a TLV is assigned to the
beacon filter API it should be updated.

Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>