arm64: dts: rockchip: move common ROCK 5B/+ nodes into own tree

A few device tree nodes are shared between ROCK 5B and ROCK 5B+ that are
not shared with ROCK 5T.

Move them into their own device tree include.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Link: https://lore.kernel.org/r/20250520-add-rock5t-v2-3-1f1971850a20@collabora.com


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