handshake: add event for rekey success

Rekeys for station mode don't need to know when complete since
there is nothing to do once done. AP mode on the other hand needs
to know if the rekey was successful in order to reset/set the next
rekey timer.

src/handshake.h

@@ -60,6 +60,7 @@ enum handshake_event {
 	HANDSHAKE_EVENT_EAP_NOTIFY,
 	HANDSHAKE_EVENT_TRANSITION_DISABLE,
 	HANDSHAKE_EVENT_P2P_IP_REQUEST,
+	HANDSHAKE_EVENT_REKEY_COMPLETE,
 };
 
 typedef void (*handshake_event_func_t)(struct handshake_state *hs,

src/station.c

@@ -1015,6 +1015,7 @@ static void station_handshake_event(struct handshake_state *hs,
 	case HANDSHAKE_EVENT_SETTING_KEYS_FAILED:
 	case HANDSHAKE_EVENT_EAP_NOTIFY:
 	case HANDSHAKE_EVENT_P2P_IP_REQUEST:
+	case HANDSHAKE_EVENT_REKEY_COMPLETE:
 		/*
 		 * currently we don't care about any other events. The
 		 * netdev_connect_cb will notify us when the connection is