P2P: Send STA connected/disconnected events to parent ctrl_iface

Send the connection events from P2P group to both the group interface
and parent interface ctrl_ifaces to make it easier for external monitor
programs to see these events without having to listen to all group
interfaces when virtual group interfaces are used.

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>

src/ap/hostapd.h

@@ -82,6 +82,7 @@ struct hostapd_data {
 				 struct sta_info *sta, int reassoc);
 
 	void *msg_ctx; /* ctx for wpa_msg() calls */
+	void *msg_ctx_parent; /* parent interface ctx for wpa_msg() calls */
 
 	struct radius_client_data *radius;
 	u32 acct_session_id_hi, acct_session_id_lo;