dt-bindings: Convert the binding file google, cros-ec-codec.txt to yaml format.

This was tested and verified with:
make dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/sound/google,cros-ec-codec.yaml

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200127091806.11403-1-dafna.hirschfeld@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>