arm64: dts: rockchip: Add rk3588 Edgeble Neu6 Model B IO

arm64: dts: rockchip: Add rk3588 Edgeble Neu6 Model B IO

Neural Compute Module 6B(Neu6B) IO board is an industrial form factor
ready-to-use IO board from Edgeble AI.

IO board offers plenty of peripherals and connectivity options and
this patch enables basic eMMC and UART which is enough to successfully
boot Linux.

General features:
- microSD slot
- 1x HDMI Out
- 1x HDMI In
- 2x DP
- 1x eDP
- 2x MIPI DSI connector
- 4x MIPI CSI2 connector
- 2x USB Host
- 2x USB 3.0 OTG/Host
- 1x SATA
- 1x 2.5Gbps Ethernet
- 1x 4G/5G mini PCIe
- 1x M.2 E-Key slot
- 1x Onboard PoE
- 1x RS485, RS232, CAN
- 1x Audio, MIC port
- RTC battery slot
- 40-pin GPIO expansion

Neu6B needs to mount on top of this IO board in order to create a
complete Edgeble Neural Compute Module 6B(Neu6B) IO platform.

Add support for Edgeble Neu6 Model B IO Board.

Signed-off-by: Jagan Teki <jagan@edgeble.ai>
Link: https://lore.kernel.org/r/20230516163454.997736-4-jagan@edgeble.ai
Signed-off-by: Heiko Stuebner <heiko@sntech.de>