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

rpi-kernel,rpi-firmware: update to 5.15.61. [ci skip]
https://github.com/void-linux/void-packages/pull/38958

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

I've built rpi4-kernel and rpi-firmware, and created an image for my CM4. It boots, haven't tested anything more so far. I sadly don't have any other Pi products to test on right now, so I'd need some other people to help on this.

cc @Piraty as current maintainer

Resolves https://github.com/void-linux/void-mklive/issues/264
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