ASoC: dt-bindings: wcd938x-sdw: add bindings for wcd938x-sdw

ASoC: dt-bindings: wcd938x-sdw: add bindings for wcd938x-sdw

Qualcomm WCD9380/WCD9385 Codec is a standalone Hi-Fi audio codec IC
connected over SoundWire. This device has two SoundWire devices RX and
TX respectively. This bindings is for those slave devices on WCD9380/WCD9385.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210609090943.7896-5-srinivas.kandagatla@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>