ARM: dts: rockchip: Add mmc aliases for rk3288-veyron devices

All of them have an internal emmc that becomes mmc0 and
devices including the sdmmc snippet get mmc1 for the external
sd slot on suitable devices.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20230307095516.4116827-1-heiko@sntech.de