ar71xx: add missing diag LED support for RB wAP 2nD

3b15eb06c366cf3805590a61f22e966a95bf8101 did not include diag.sh
edit

Signed-off-by: Thibaut VARÈNE <[email protected]>

target/linux/ar71xx/base-files/etc/diag.sh

@@ -375,7 +375,8 @@ get_status_led() {
 	rb-962uigs-5hact2hnt|\
 	rb-lhg-5nd|\
 	rb-map-2nd|\
-	rb-mapl-2nd)
+	rb-mapl-2nd|\
+	rb-wap-2nd)
 		status_led="rb:green:user"
 		;;
 	rb-951ui-2hnd)