rockchip: rk3308: fix same-as-spl boot order

Boot devices defined in rk3308.c and in rk3308.dtsi do not match, causing
'same-as-spl' feature not to work. Update DTS definitions, aligning to
Linux kernel DTS and to other Rockchip DTS files, i.e. from dwmmc to mmc.

Add rk3308-rock-pi-s.dtb in dtb-y targets for CONFIG_ROCKCHIP_RK3308.

Signed-off-by: Massimo Pegorer <massimo.pegorer@vimar.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
2 files changed