local_node: query client MBO support from hostapd

Query client MBO support from hostapd and display it in the output of
the connected_clients ubus method as "multi-band-operation".

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>

usteer.h

@@ -246,6 +246,7 @@ struct sta_info {
 
 	uint8_t rrm;
 	bool bss_transition;
+	bool mbo;
 
 	enum roam_trigger_state roam_state;
 	uint8_t roam_tries;