NanoPi R4S patch overwriting mainline base DTS, needs refactored

Mainline device tree now exists for the NanoPi R4S, the support patches for it need to be refactored to use that dts as base instead of introducing a new one from scratch. As kernel 6.1 is likely an LTS this activity should be completed before the 23.02 release as part of the Rockchip64 cleanup.