ASoC: cros_ec_codec: Add codec driver for Cros EC

Add a codec driver to control ChromeOS EC codec.

Use EC Host command to enable/disable I2S recording and control other
configurations.

Signed-off-by: Cheng-Yi Chiang <cychiang@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Mark Brown <broonie@kernel.org>