arm64: dts: rockchip: add Firefly Core-PX30-JD4 SoM

arm64: dts: rockchip: add Firefly Core-PX30-JD4 SoM

The Firefly Core-PX30-JD4 SoM is a 69.6x49.6mm (260 pin SODIMM connector)
system-on-module from Firefly, featuring the Rockchip PX30.

It provides the following feature set:
 * on-module DDR3 (1GB/2GB)
 * on-module eMMC 5.1 (8GB/16GB/32GB/64GB/128GB)
 * on-module NPU (optional)
 * SD card (on a baseboard) via edge connector
 * 100mbps Ethernet (on a baseboard) via edge connector
 * MIPI-DSI (on a baseboard) via edge connector
 * Audio (on a baseboard) via edge connector
   - 1x SPDIF
   - 1x 8-channel I2S/TDM
   - 1x 2-channel I2S/TDM
   - 1x 8-channel PDM
 * USB (on a baseboard) via edge connector
   - 1x USB 2.0 OTG
   - 1x USB 2.0 host
 * Various GPIO (on a baseboard) via edge connector

Signed-off-by: Christopher Obbard <chris.obbard@collabora.com>
Link: https://lore.kernel.org/r/20240718-rockchip-px30-firefly-v3-2-3835cdd22eae@collabora.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>