[Task]: Integrate families `rockpis` and `rock-s0` into the `rockchip64` family

### Task description

Both of these families are only for one specific board and can be easily integreated into `rockchip64` as discussed in https://github.com/armbian/build/pull/6879#issuecomment-2205910238 and also [in the forums](https://forum.armbian.com/topic/32916-ideas-on-how-to-make-soc-family-patches-more-manageable/).

- [ ] Move all stuff that is specific to the board into the board's config (no board conditionals in family config)
- [ ] Move everything not board-specific into `rockchip64` config
- [ ] Integrate kernel patches into `rockchip64` where applicable
- [ ] Remove kernel configs

Assigning to @brentr as discussed in https://github.com/armbian/build/issues/6821#issuecomment-2205234200
Please note that this won't be done before september:
> I will "move stuff" out of the RockPI-S family in September, after I can test again

If anyone else wants to take up the task though, feel free to do so and discuss with @brentr .