ASoC: rockchip: support ACODEC for rk3328

This patch adds support for audio CODEC core of rk3328.

Rockchip does not publish detail specification of this core
but driver source code is opened on their GitHub repository.
https://github.com/rockchip-linux/kernel

So I ported this code to linux-next and added some trivial fixes.

Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
Signed-off-by: Mark Brown <broonie@kernel.org>