arm64: dts: rockchip: add dts for Firefly Station P2 aka rk3568-roc-pc

Add dts for Firefly Station P2.
Working IO:
* eMMC
* HDMI
* LAN
* LED
* SD Card
* UART
* USB2
* USB3

Signed-off-by: Furkan Kardame <f.kardame@manjaro.org>
Link: https://lore.kernel.org/r/20230620184746.55391-3-f.kardame@manjaro.org


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