ASoC: codecs: wcd938x: add basic driver

This patch adds basic SoundWire codec driver to support for
WCD938X TX and RX devices.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210609090943.7896-4-srinivas.kandagatla@linaro.org


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