[U-Boot] [U-Boot, 3/4] rockchip: rk3188: add u-boot-specific mmc properties

[Philipp Tomsich]

> The dwmmc controllers on rk3188 do not have idma support, so need to
> use the fifo-mode and it my tests they became confused and stopped
> working if the frequency was to high.
> 
> While I only tested in somewhat bigger steps, 32MHz for example
> hung the controller, while reducing it to 16MHz worked just fine
> and is reasonably fast to load a kernel from mmc.
> 
> Signed-off-by: Heiko Stuebner <heiko at sntech.de>
> Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> Acked-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> ---
>  arch/arm/dts/rk3188-radxarock-u-boot.dtsi | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 

Applied to u-boot-rockchip, thanks!