ARM: dts: exynos: add function and color to LED node in Odroid XU4

Add common LED properties - the function and color - to LED node in
Exynos5422 Odroid XU4, so we can drop deprecated label property.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/arm/boot/dts/exynos5422-odroidxu4.dts

···
  */
 
 /dts-v1/;
+#include <dt-bindings/leds/common.h>
 #include <dt-bindings/sound/samsung-i2s.h>
 #include "exynos5422-odroidxu3-common.dtsi"
 
···
 		compatible = "pwm-leds";
 
 		led-1 {
-			label = "blue:heartbeat";
+			function = LED_FUNCTION_HEARTBEAT;
+			color = <LED_COLOR_ID_BLUE>;
 			pwms = <&pwm 2 2000000 0>;
 			pwm-names = "pwm2";
 			max-brightness = <255>;