[U-Boot] [U-Boot, 3/3] rockchip: firefly-rk3399: enable ATF and dwmmc

[Philipp Tomsich]

> enable the ATF option and SDCard in defconfig.
> 
> Signed-off-by: Kever Yang <kever.yang at rock-chips.com>
> Acked-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> ---
> 
>  configs/firefly-rk3399_defconfig | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 

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