ASoC: dt-bindings: linux,spdif: Convert spdif-reciever.txt to dtschema

Convert the dummy SPDIF receiver bindings to DT schema.

Signed-off-by: Animesh Agarwal <animeshagarwal28@gmail.com>
Cc: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240606041212.78428-1-animeshagarwal28@gmail.com


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