[U-Boot] [U-Boot, 5/7] rockchip: firefly-rk3399: dts: enable sdmmc device

[Philipp Tomsich]

> Enable sdmmc device and add the spl boot device sequence.
> 
> Signed-off-by: Kever Yang <kever.yang at rock-chips.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> ---
> 
>  arch/arm/dts/rk3399-firefly.dts | 7 +++++++
>  1 file changed, 7 insertions(+)
> 

Applied to u-boot-rockchip/next, thanks!