rockchip: Add support for RK3568 LinkEase EasePi R1

rockchip: Add support for RK3568 LinkEase EasePi R1

Specification:
- Rockchip RK3568
- 2GB/4GB LPDDR4 RAM
- 16GB on-board eMMC
- 1x M.2 key for 2280 NVMe (PCIe 3.0)
- 1x USB 3.0 Type-A
- 1x USB 2.0 Type-C (for USB flashing)
- 2x 1000 Base-T (native, RTL8211F)
- 2x 2500 Base-T (PCIe, RTL8125B)
- 1x HDMI 2.0 Output
- 12v DC Jack
- 1x Power key connected to PMIC
- 2x LEDs (one static power supplied, one GPIO controlled)

Debug Serial Port: 3.3V TTL, 3-pin 2.54mm pitch connector, 1500000 bauds,
'J7' on board with G/R/T (GND/RX/TX) pins marked

Installation - eMMC:
-Boot official firmware (OpenWRT based)
-Upload sysupgrade.img.gz to /tmp/firmware.bin (with scp or web page)
-Flash to eMMC: sysupgrade -n -p -F /tmp/firmware.bin

Signed-off-by: Liangbin Lian <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/20147
Signed-off-by: Hauke Mehrtens <[email protected]>