rockchip: add support for PX30 Ringneck SoM on Haikou Devkit

The PX30-µQ7 (Ringneck) is a system-on-module featuring the Rockchip
PX30 in a micro Qseven-compatible form-factor.

PX30-µQ7 features:
        * CPU: quad-core Cortex-A35
        * DRAM: 2GB dual-channel
        * eMMC: onboard eMMC
        * SD/MMC
        * TI DP83825I 10/100Mbps PHY
        * USB:
                * USB2.0 dual role port
                * 3x USB2.0 host via onboard USB2.0 hub
        * Display: MIPI-DSI
        * Camera: MIPI-CSI
        * onboard 2.4GHz WiFi + Bluetooth module
        * Companion Controller: on-board additional microcontroller
	  (STM32 Cortex-M0 or ATtiny):
                * RTC
                * fan controller
                * CAN (only STM32)

The non-U-Boot DTS files are imported from Linux v6.2-rc2.

Cc: Quentin Schulz <foss+uboot@0leil.net>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>