There is no "max_brightness" property as pointed out by dtschema:

  arch/arm/boot/dts/exynos5422-odroidxu4.dt.yaml: led-controller: led-1: 'max-brightness' is a required property

Fixes: 6658356014cb ("ARM: dts: Add support Odroid XU4 board for exynos5422-odroidxu4")
Signed-off-by: Krzysztof Kozlowski <redacted>
---
 arch/arm/boot/dts/exynos5422-odroidxu4.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/exynos5422-odroidxu4.dts b/arch/arm/boot/dts/exynos5422-odroidxu4.dts
index ede782257643..1c24f9b35973 100644
--- a/arch/arm/boot/dts/exynos5422-odroidxu4.dts
+++ b/arch/arm/boot/dts/exynos5422-odroidxu4.dts

@@ -24,7 +24,7 @@ led-1 {
 			label = "blue:heartbeat";
 			pwms = <&pwm 2 2000000 0>;
 			pwm-names = "pwm2";
-			max_brightness = <255>;
+			max-brightness = <255>;
 			linux,default-trigger = "heartbeat";
 		};
 	};

-- 
2.25.1