dt-bindings: ASoC: Add WSA881x bindings

This patch adds bindings for WSA8810/WSA8815 Class-D Smart Speaker
Amplifier. This Amplifier also has a simple thermal sensor for
over temperature and speaker protection.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200107135929.3267-2-srinivas.kandagatla@linaro.org


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