ipu6-softisp

This code adds support for the ipu6 webcams via libcamera, based on the work in https://copr.fedorainfracloud.org/coprs/jwrdegoede/ipu6-softisp/.

It's supposed to be included in your NixOS configuration imports, and will:

Add some patches to your kernel, which should apply on 6.7.x
Add the ipu6-camera-bins firmware (still needed)
Enable some kernel config options
Add an udev rule so libcamera can do DMABUF things
Override services.pipewire.package and services.pipewire.wireplumber.package to use a pipewire built with a libcamera with support for this webcam.

Please make sure you don't have any of the hardware.ipu6 options still enabled, as they use the closed-source userspace stack and will conflict.

qcam can be found in libcamera-qcam (pending on https://github.com/NixOS/nixpkgs/pull/284964 to trickle into master).

Thanks to Hans de Goede for helping me bringing this up, as well as to puckipedia for sorting out some pipewire-related confusion.