arm64: dts: rockchip: Add Radxa CM3J

The Radxa CM3J is a feature rich industrial compute module based on
the Rockchip RK3568J SoC. [1]

Specification:
- Quad-core Cortex-A55 CPU
- Mali-G52 2EE GPU
- 1TOPS NPU
- Up to 8GB LPDDR4x RAM
- Up to 32GB eMMC (optional)
- 16MB SPI flash (optional)
- Wi-Fi 5 / BT 5.0 with external antenna connector
- Gigabit Ethernet PHY
- RK809 PMIC
- Green (power) LED

[1] https://dl.radxa.com/cm3j/docs/hw/radxa_cm3j_schematic_v1.2_20250115.pdf

Signed-off-by: FUKAUMI Naoki <naoki@radxa.com>
Link: https://patch.msgid.link/20260108113341.14037-2-naoki@radxa.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: RadxaNaoki