arm64: dts: rockchip: Add base DT for rk3528 SoC

This initial device tree describes CPU, interrupts and UART on the chip
and is able to boot into basic kernel with only UART. Cache information
is omitted for now as there is no precise documentation. Support for
other features will be added later.

Signed-off-by: Yao Zi <ziyao@disroot.org>
Link: https://lore.kernel.org/r/20240829092705.6241-4-ziyao@disroot.org


Signed-off-by: Heiko Stuebner <heiko@sntech.de>