ARM: dts: exynos: fix PWM LED max brightness on Odroid HC1

ARM: dts: exynos: fix PWM LED max brightness on Odroid HC1

[ Upstream commit a7e59c84cf2055a1894f45855c8319191f2fa59e ]

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

  arch/arm/boot/dts/exynos5422-odroidhc1.dt.yaml: led-controller: led-1: 'max-brightness' is a required property

Fixes: 9334cbcd4d14 ("ARM: dts: exynos: Add support for Hardkernel's Odroid HC1 board")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210505135941.59898-4-krzysztof.kozlowski@canonical.com
Signed-off-by: Sasha Levin <sashal@kernel.org>