ARM: dts: rockchip: set FIFO size for SDMMC, SDIO and EMMC on rk3066 and rk3188

The SDMMC, SDIO and EMMC controllers use an external FIFO whose size is 256x32bit.
This patch set the corresponding fifo-depth properties for both RK3066 and RK3188.

Signed-off-by: Julien CHAUVEAU <julien.chauveau@neo-technologies.fr>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>