ASoC: dt-bindings: Convert Bluetooth SCO Link binding to a schema

ASoC: dt-bindings: Convert Bluetooth SCO Link binding to a schema

Bluetooth SCO Link are supported by 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 driver over to a YAML schema.

Cc: alsa-devel@alsa-project.org
Cc: devicetree@vger.kernel.org
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Samuel Holland <samuel@sholland.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20210901091852.479202-3-maxime@cerno.tech
Signed-off-by: Mark Brown <broonie@kernel.org>