IPU6 drivers fail to build in NixOS 24.11 (already fixed on unstable)

[jheidbrink]

Steps To Reproduce

Steps to reproduce the behavior:

build a config containing

hardware.ipu6.enable = true;
hardware.ipu6.platform = "ipu6ep";

on the 24.11 branch.

Additional context

There is a fix in #357050 but it's not backported to 24.11.
See discourse thread https://discourse.nixos.org/t/upgrade-to-nixos-24-11-fails-due-to-ipu6-driver/57622/3

Notify maintainers

CC @flokl as you authored #357050 and @matejc as you reviewed the PR

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/upgrade-to-nixos-24-11-fails-due-to-ipu6-driver/57622/5