ASoC: jz4740-i2s: Convert to regmap API

Using regmap for accessing the AIC registers makes the driver a
little easier to read, and later refactors can take advantage of
regmap APIs to further simplify the driver.

Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Link: https://lore.kernel.org/r/20221023143328.160866-3-aidanmacdonald.0x0@gmail.com


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