[U-Boot] [U-Boot,2/4] rockchip: Add an I2S driver

[Philipp Tomsich]

> Add a driver for I2S which allows audio data to be sent from the SoC to
> the audio codec. The sample rate and other settings are hard-coded for now
> as there is no suitable device-tree binding available.
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> 
>  drivers/sound/Kconfig        |   9 +++
>  drivers/sound/Makefile       |   1 +
>  drivers/sound/rockchip_i2s.c | 149 +++++++++++++++++++++++++++++++++++
>  3 files changed, 159 insertions(+)
>  create mode 100644 drivers/sound/rockchip_i2s.c
> 

Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>