iwlwifi: mvm: Always use SCAN_TYPE_FORCED

The FW AUX framework does not handle well cases where time events
fail to be scheduled (and as a result issues assert 0x3330). Until
a proper fix is in place, WA this by always setting the scan type to
SCAN_TYPE_FORCED.

Cc: stable@vger.kernel.org
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>