rockchip: add support for Radxa ROCK 5 ITX/ITX+

rockchip: add support for Radxa ROCK 5 ITX/ITX+

The Radxa ROCK 5 ITX(+) is a Mini-ITX form factor computer using the
Rockchip RK3588 SoC.

- https://radxa.com/products/rock5/5itx
- https://radxa.com/products/rock5/5itxp

Hardware
--------

- Quad Cortex-A76 and Quad Cortex-A55 CPU
- Mali-G610 MP4 GPU
- 6 TOPS NPU
- 4/8/16/24/32GB LPDDR5 RAM
- on-board eMMC
- 16MB SPI NOR flash
- microSD card slot
- 2x 2.5 Gigabit Ethernet ports with PoE (additional PoE module required)
- USB 3.1 Gen1 Type-C HOST/OTG port
- 4x USB 3.1 Gen1 Type-A HOST ports
- 2x USB 2.0 Type-A HOST ports
- M.2 M Key connector with PCIe 3.0 x2
- 4x SATA connectors (ITX only)
- 2nd M.2 M Key connector with PCIe 3.0 x2 (ITX+ only)
- M.2 E Key connector with PCIe 2.1 x1 and USB 2.0
- RTC battery socket for CR1220
- 4pin PWM fan connector
- Serial console pin header
- Front panel pin headers
- 24pin ATX power connector
- 5525 12V DC jack

Installation
------------

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

Signed-off-by: FUKAUMI Naoki <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/19867
Signed-off-by: Hauke Mehrtens <[email protected]>