arm64: dts: rockchip: Update eMMC, SD aliases for Radxa SBC boards

Radxa SBC boards like ROCK 3A/4 models do support eMMC and SDcard
via external connector slots.

Mark, the eMMC has mmc0 by considering the Rockchip boot order priority
as both MMC devices are connected externally.

Reported-by: FUKAUMI Naoki <naoki@radxa.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Link: https://lore.kernel.org/r/20230118080454.11643-2-jagan@amarulasolutions.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>