dt-bindings: sound: Convert Samsung Exynos Odroid XU3/XU4 audio complex to dt-schema

Convert Samsung Exynos Odroid XU3/XU4 audio complex with MAX98090 codec
to newer dt-schema format.

'clocks' property is unneeded in the bindings and is left undefined in 'properties'.

'samsung,audio-widgets' and 'samsung,audio-routing' are optional from driver
perspective and they are set as unrequired.

Signed-off-by: Maciej Falkowski <m.falkowski@samsung.com>
[mszyprow: reordered non-standard properties]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191017100529.4183-1-m.szyprowski@samsung.com


Signed-off-by: Mark Brown <broonie@kernel.org>