arm64: dts: st: Add boot-led for stm32mp2 ST boards

Add options/u-boot/boot-led property to specify to U-Boot
the LED which indicates a successful boot.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20251112-upstream_add_boot-led_for_stm32_boards-v1-13-50a3a9b339a8@foss.st.com
Link: https://lore.kernel.org/r/20251112-upstream_add_boot-led_for_stm32_boards-v1-14-50a3a9b339a8@foss.st.com
Link: https://lore.kernel.org/r/20251112-upstream_add_boot-led_for_stm32_boards-v1-15-50a3a9b339a8@foss.st.com
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

Author: Patrice Chotard

arch/arm64/boot/dts/st/stm32mp235f-dk.dts

@@ -46,7 +46,7 @@
 	gpio-leds {
 		compatible = "gpio-leds";
 
-		led-blue {
+		led_blue: led-blue {
 			function = LED_FUNCTION_HEARTBEAT;
 			color = <LED_COLOR_ID_BLUE>;
 			gpios = <&gpioh 7 GPIO_ACTIVE_HIGH>;
@@ -70,6 +70,13 @@
 		reg = <0x0 0x80000000 0x0 0x80000000>;
 	};
 
+	options {
+		u-boot {
+			compatible = "u-boot,config";
+			boot-led = <&led_blue>;
+		};
+	};
+
 	reserved-memory {
 		#address-cells = <2>;
 		#size-cells = <2>;

arch/arm64/boot/dts/st/stm32mp257f-dk.dts

@@ -46,7 +46,7 @@
 	gpio-leds {
 		compatible = "gpio-leds";
 
-		led-blue {
+		led_blue: led-blue {
 			function = LED_FUNCTION_HEARTBEAT;
 			color = <LED_COLOR_ID_BLUE>;
 			gpios = <&gpioh 7 GPIO_ACTIVE_HIGH>;
@@ -70,6 +70,13 @@
 		reg = <0x0 0x80000000 0x1 0x0>;
 	};
 
+	options {
+		u-boot {
+			compatible = "u-boot,config";
+			boot-led = <&led_blue>;
+		};
+	};
+
 	reserved-memory {
 		#address-cells = <2>;
 		#size-cells = <2>;

arch/arm64/boot/dts/st/stm32mp257f-ev1.dts

@@ -46,7 +46,7 @@
 	gpio-leds {
 		compatible = "gpio-leds";
 
-		led-blue {
+		led_blue: led-blue {
 			function = LED_FUNCTION_HEARTBEAT;
 			color = <LED_COLOR_ID_BLUE>;
 			gpios = <&gpioj 7 GPIO_ACTIVE_HIGH>;
@@ -94,6 +94,13 @@
 		reg = <0x0 0x80000000 0x1 0x0>;
 	};
 
+	options {
+		u-boot {
+			compatible = "u-boot,config";
+			boot-led = <&led_blue>;
+		};
+	};
+
 	panel_lvds: display {
 		compatible = "edt,etml0700z9ndha", "panel-lvds";
 		enable-gpios = <&gpiog 15 GPIO_ACTIVE_HIGH>;