ARM: dts: rockchip: Add SDIO0 node for VMARC SOM

Rockchip RK3288 and RK3399Pro based VMARC SOM has sdio0 for
connecting WiFi/BT devices as a pluggable card via M.2 E-Key.

Add associated sdio0 nodes, properties.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Link: https://lore.kernel.org/r/20201023181814.220974-2-jagan@amarulasolutions.com


[moved the unrelated rtc addition to a separate patch]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>