ASoC: dt-bindings: maxim,max98504: Convert to DT schema

Convert the Maxim Integrated MAX98504 amplifier bindings to DT schema.
Few properties are made optional:
1. interrupts: current Linux driver implementation does not use them,
2. supplies: on some boards these might be wired to battery, for which
   no regulator is provided.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221204113621.151303-1-krzysztof.kozlowski@linaro.org


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