arm64: dts: rockchip: add rga3 dt nodes to rk3588

arm64: dts: rockchip: add rga3 dt nodes to rk3588

Add devicetree nodes for the RGA3 (Raster Graphics Acceleration 3)
peripheral in the RK3588.

The existing rga node refers to the RGA2-Enhanced peripheral. The RK3588
contains one RGA2-Enhanced core and two RGA3 cores. Both feature a similar
functionality of scaling, cropping and rotating of up to two input
images into one output image. Key differences of the RGA3 are:

- supports 10bit YUV output formats
- supports 8x8 tiles and FBCD as inputs and outputs
- supports BT2020 color space conversion
- max output resolution of (8192-64)x(8192-64)
- MMU can map up to 32G DDR RAM
- fully planar formats (3 planes) are not supported
- max scale up/down factor of 8 (RGA2 allows up to 16)

Signed-off-by: Sven Püschel <s.pueschel@pengutronix.de>
Link: https://patch.msgid.link/20260521-spu-rga3-v7-28-3f33e8c7145f@pengutronix.de
Signed-off-by: Heiko Stuebner <heiko@sntech.de>