lantiq: add support for upgrade led

Indicate a (sys)upgrade via leds as well. It brings the lantiq diag.sh
script en par with the other implementations using devicetree aliases
to define multiple leds for boot status indication.

By default, use the boot finished led to indicate an upgrade for now.

Signed-off-by: Mathias Kresin <dev@kresin.me>

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

@@ -6,6 +6,7 @@
 boot="$(get_dt_led boot)"
 failsafe="$(get_dt_led failsafe)"
 running="$(get_dt_led running)"
+upgrade="$(get_dt_led upgrade)"
 
 set_state() {
 	status_led="$boot"
@@ -26,6 +27,14 @@ set_state() {
 	preinit_regular)
 		status_led_blink_preinit_regular
 		;;
+	upgrade)
+		[ -n "$running" ] && {
+			status_led="$running"
+			status_led_off
+		}
+		status_led="$upgrade"
+		status_led_blink_preinit_regular
+		;;
 	done)
 		status_led_off
 		[ -n "$running" ] && {