ASoC: dt-bindings: Convert Allwinner A10 codec to a schema

ASoC: dt-bindings: Convert Allwinner A10 codec to a schema

The Allwinner SoCs have an embedded audio codec that is supported in Linux,
with a matching Device Tree binding.

Now that we have the DT validation in place, let's convert the device tree
bindings for that controller over to a YAML schemas.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191016104355.65169-1-mripard@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>