arm64: dts: rockchip: nanopc-t6 sdmmc beautification

drop max-frequency = <200000000> as it is already defined in rk3588s.dtsi
order no-sdio & no-mmc properties while we are here

Signed-off-by: John Clark <inindev@gmail.com>
Link: https://lore.kernel.org/r/20231228173011.2863-1-inindev@gmail.com


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