New review comment by ahesford on void-packages repository

https://github.com/void-linux/void-packages/pull/26000#discussion_r554727891

Comment:
I don't like the idea of a separate `rpi4-base` because the distinction is arbitrary. The problem compounds when there is a Raspberry Pi 5 and so on. Suddenly every new hardware release that requires a different kernel gets paired with a new `-base` just to pull in that kernel.

The only difference needed to move from rpi3 to rpi4 is the kernel, so let's decouple the kernel from the base and keep things consistent.