ARM: dts: stm32: add heartbeat led for stm32mp157c-ed1

Add heartbeat led for stm32mp157c-ed1.
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

arch/arm/boot/dts/st/stm32mp157c-ed1.dts

@@ -10,6 +10,7 @@
 #include "stm32mp15-pinctrl.dtsi"
 #include "stm32mp15xxaa-pinctrl.dtsi"
 #include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/leds/common.h>
 #include <dt-bindings/mfd/st,stpmic1.h>
 
 / {
@@ -71,6 +72,17 @@ retram: retram@38000000 {
 		};
 	};
 
+	led {
+		compatible = "gpio-leds";
+		led-blue {
+			gpios = <&gpiod 9 GPIO_ACTIVE_HIGH>;
+			linux,default-trigger = "heartbeat";
+			default-state = "off";
+			function = LED_FUNCTION_HEARTBEAT;
+			color = <LED_COLOR_ID_BLUE>;
+		};
+	};
+
 	sd_switch: regulator-sd_switch {
 		compatible = "regulator-gpio";
 		regulator-name = "sd_switch";