ASoC: convert rk3328 codec binding to yaml

This patch converts Rockchip rk3328 audio codec binding to DT schema.
And adds description about "mclk" clock and fixes some errors in
original example.

Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200714073247.172859-1-katsuhiro@katsuster.net


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