dt-bindings: sound: gtm601: convert to YAML

Convert GTM601 binding to the YAML format.

Signed-off-by: David Heidelberg <david@ixit.cz>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230730191742.117013-1-david@ixit.cz


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