rockchip: Use files from dts/upstream

rockchip: Use files from dts/upstream

Most Rockchip aarch64 targets have now migrated to use OF_UPSTREAM,
however a few of the old dtsi and dt-bindings files still remain.

Remove remaining common dtsi and header files that can be included
directly from dts/upstream to prevent possible issues when future tags
from devicetree-binding is merged. No changes is expected with this.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>