rockchip: add support for Radxa ZERO 3E and 3W

rockchip: add support for Radxa ZERO 3E and 3W

Radxa ZERO 3E and 3W are light, compact and tiny SBC[1][2] using the
Rockchip RK3566.

Hardware
--------
- Rockchip RK3566 SoC
- Quad A55 CPU
- Mali-G52-2EE GPU
- 1 TOPS @ INT8 NPU
- 1GB/2GB/4GB/8G LPDDR4 RAM
- Optional 8GB/16GB/32GB/64GB eMMC (3E)
- Micro SD Card slot
- 1x Gigabit ethernet port (supports PoE with add-on PoE HAT) (3E)
- WiFi6/BT5.4 (3W) (not supported yet on OpenWrt)
- 1x USB 3.0 Type-C HOST port
- 1x USB 2.0 Type-C OTG port
- Optional 40 Pin GPIO header

[1] https://radxa.com/products/zeros/zero3e
[2] https://radxa.com/products/zeros/zero3w

Installation
------------
Uncompress the OpenWrt sysupgrade and write it to a micro SD card or
internal eMMC using dd.

Signed-off-by: FUKAUMI Naoki <naoki@radxa.com>
Link: https://github.com/openwrt/openwrt/pull/16185
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>