iwlwifi: mvm: use proper scan type for P2P

It was set to be FORCED because of a firmware bug which
has been fixed.

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