rework bssid handling and stop all used bssids when leaving RUN

Instead of haing a pool of unsused BSS Id's and a list of active
BSS's (wlans), use a single array and only mark the BSS Id as used
or unused.

When leaving RUN state, release (stop) all used BSS.

src/wtp/wtp_dfa.c

@@ -571,6 +571,7 @@ void wtp_dfa_retransmition_timeout(struct capwap_timeout* timeout, unsigned long
 void wtp_reset_state(void)
 {
 	/* reset WTP state */
+	wtp_radio_reset();
 
 	wtp_free_reference_last_request();
 	wtp_free_reference_last_response();