ASoC: dt-bindings: asahi-kasei,ak4458: fix missing quotes around hash

The yamllint expect comments to start with hash and space ('# '), so
quote the description to fix:

  asahi-kasei,ak4458.yaml:40:30: [error] missing starting space in comment (comments)

Reported-by: Rob Herring <robh@kernel.org>
Closes: https://lore.kernel.org/all/CAL_JsqJzxQb1g=yVgHduLnYOpk8-Q3jppA1qQT1Ce51_gNWjhg@mail.gmail.com/


Fixes: 009e83b5 ("ASoC: dt-bindings: ak4458: Convert to dtschema")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230407170032.102412-1-krzysztof.kozlowski@linaro.org


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