iwlwifi: mvm: Fix broadcast filtering

Current code did not allow sending the broadcast filtering command
for P2P Client interfaces. However, this was not enough, since once
broadcast filtering command was issued over the station interface
after the P2P Client connected, the command also attached the filters
to the P2P Client MAC which is not allowed (FW ASSERT 1063).

Fix this skipping P2P Client interfaces when constructing the broadcast
filtering command

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: ArikX Nemtsov <arik@wizery.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>