arm64: dts: rockchip: Add nodes for NPU and its MMU to rk3588-base

arm64: dts: rockchip: Add nodes for NPU and its MMU to rk3588-base

See Chapter 36 "RKNN" from the RK3588 TRM (Part 1).

The IP is divided in three cores, programmed independently. The first
core though is special, being able to delegate work to the other cores.

The IOMMU of the first core is also special in that it has two subunits
(read/write?) that need to be programmed in sync.

v2:
- Have one device for each NPU core (Sebastian Reichel)
- Have one device for each IOMMU (Sebastian Reichel)
- Correctly sort nodes (Diederik de Haas)
- Add rockchip,iommu compatible to IOMMU nodes (Sebastian Reichel)

v3:
- Adapt to a split of the register block in the DT bindings (Nicolas
  Frattaroli)

v4:
- Adapt to changes in bindings

v6:
- pclk and npu clocks are needed by all clocks (Rob Herring)

v8:
- Remove notion of top core (Robin Murphy)

Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Tomeu Vizoso <tomeu@tomeuvizoso.net>
Link: https://lore.kernel.org/r/20250721-6-10-rocket-v9-8-77ebd484941e@tomeuvizoso.net
Signed-off-by: Heiko Stuebner <heiko@sntech.de>