hostapd: include vlan_id in sta-authorized event

There are use cases where it's helpful to know the vlan_id assigned to a
client (dynamic VLAN) when consuming the sta-authorized ubus event

Signed-off-by: Paul White <paul@shasta.cloud>

feeds/wifi-ax/hostapd/patches/x-0005-add-vlan_id-to-sta-authorized-event.patch

@@ -0,0 +1,11 @@
+--- a/src/ap/ubus.c
++++ b/src/ap/ubus.c
+@@ -1914,6 +1914,8 @@ void hostapd_ubus_notify_authorized(stru
+ 	blob_buf_init(&b, 0);
+ 	blobmsg_add_macaddr(&b, "address", sta->addr);
+ 	blobmsg_add_string(&b, "ifname", hapd->conf->iface);
++	if (sta->vlan_id)
++		blobmsg_add_u32(&b, "vlan_id", sta->vlan_id);
+ 	if (sta->bandwidth[0] || sta->bandwidth[1]) {
+ 		void *r = blobmsg_open_array(&b, "rate-limit");
+