ath79: add support for indicating the boot state using multiple leds

Use diag.sh version used for apm821xx, ipq40xx and ipq806x, which
supports different leds for the different boot states.

The existing led sequences should be the same as before.

Signed-off-by: Dmitry Tunin <hanipouspilot@gmail.com>
[reword commit message]
Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/ath79/base-files/etc/diag.sh

@@ -2,21 +2,46 @@
 
 . /lib/functions/leds.sh
 
-status_led="$(get_dt_led status)"
+boot="$(get_dt_led boot)"
+failsafe="$(get_dt_led failsafe)"
+running="$(get_dt_led running)"
+upgrade="$(get_dt_led upgrade)"
+
+get_status_led() {
+	status_led="$boot"
+}
 
 set_state() {
+	status_led="$boot"
+
 	case "$1" in
 	preinit)
 		status_led_blink_preinit
 		;;
 	failsafe)
+		status_led_off
+		[ -n "$running" ] && {
+			status_led="$running"
+			status_led_off
+		}
+		status_led="$failsafe"
 		status_led_blink_failsafe
 		;;
 	preinit_regular)
 		status_led_blink_preinit_regular
 		;;
+	upgrade)
+		[ -n "$running" ] && {
+			status_led="$upgrade"
+			status_led_blink_preinit_regular
+		}
+		;;
 	done)
-		status_led_on
+		status_led_off
+		[ -n "$running" ] && {
+			status_led="$running"
+			status_led_on
+		}
 		;;
 	esac
 }