rockchip: rk3399: enable spl-fifo-mode for sdmmc

adapting commit fa2047c4 ("rockchip: rk3328: enable spl-fifo-mode
for emmc and sdmmc") for rk3399.
Since mmc to sram can't do dma, add patch to prevent aborts transferring
TF-A parts.

Signed-off-by: Deepak Das <deepakdas.linux@gmail.com>