arm64: dts: rockchip: Add FriendlyARM NanoPi R5C

FriendlyARM NanoPi R5C is an open-sourced mini IoT gateway device.

Specification:
- Rockchip RK3568
- 1/4GB LPDDR4X RAM
- 8/32GB eMMC
- SD card slot
- M.2 Connector
- 2x USB 3.0 Port
- 2x 2500 Base-T (PCIe, r8125)
- HDMI 2.0
- MIPI DSI/CSI
- USB Type C 5V

Signed-off-by: Tianling Shen <cnsztl@gmail.com>
Link: https://lore.kernel.org/r/20230318083745.6181-4-cnsztl@gmail.com


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