arm64: dts: rockchip: Add Turing RK1 SoM support

The Turing RK1 is an upcoming RK3588-based SoM from Turing Machines,
designed on the Jetson SO-DIMM form factor and meant to be compatible
with most Jetson carrier boards (but especially the Turing Pi 2 cluster
board from the same vendor). It has the typical I/O you'd expect from
a Jetson board, including:

- Two UARTs (UART9 for console, UART2 is auxiliary)
- PCI Express (2.0 x1 + 3.0 x4)
- Gigabit Ethernet
- On-board eMMC
- PWM fan w/ tach
- USB-OTG [1]
- HDMI and MIPI DSI [1]
- Miscellaneous external GPIO, I²C, SPI lines [1]

Beyond that, it is pretty similar to the RK3588 EVB (in terms of PMICs,
RTC, etc).

While this is absolutely a SoM, it is a little bit special in that it's
marketed directly to users as a compute node, while most SoMs are
intended to be a part/module incorporated into a larger system. Because
of this, a majority of the users will be treating the RK1 less like a
SoM and more like a miniature "blade server."

This patch introduces a dtsi to enable most[1] of the SoM I/O, as well
as a dts catered more directly to the "compute node" use case.

[1] These peripherals are not addressed with this patch.

Signed-off-by: Sam Edwards <CFSworks@gmail.com>
Link: https://lore.kernel.org/r/20231011225823.2542262-4-CFSworks@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>