There's a merged pull request on the void-packages repository

rpi*-kernel: update to 5.15.68, merge templates
https://github.com/void-linux/void-packages/pull/39442

Description:
<!-- Uncomment relevant sections and delete options which are not applicable -->

#### Testing the changes
- I tested the changes in this PR: **YES**

### TODO
- [x] test if `zImage` works for `aarch64*` (it might, according to [the note here](https://www.raspberrypi.com/documentation/computers/config_txt.html#arm_64bit))
    - the correct target is `Image.gz`
- [x] test upgrade on all platforms
     - [x] rpi1 (armv6l)
     - [x] rpi0 (armv6l)
     - [x] rpi2 (armv7l)
     - [x] rpi3 (aarch64)
     - [x] rpi02 (aarch64)
     - [x] rpi4 (aarch64)
 - [x] matching changes to documentation - void-linux/void-docs#710
 - [x] matching changes to mklive - void-linux/void-mklive#283
 - [x] matching changes to website - void-linux/void-linux.github.io#183

pre-built packages can be found here: https://devspace.voidlinux.org/abby/rpi-merge, just add as a repo and update

closes #39174
closes #39129