common/gpu/intel/opencl: add opencl

[Kiskae]

Description of changes

Updates intel libraries as per NixOS/nixpkgs#205648
Adds module for intel opencl currently only supporting GPU

It is possible to add CPU OpenCL support, but only using an older version of the driver: https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=intel-opencl-runtime

Things done

• Tested the changes in your own NixOS Configuration
• Tested the changes end-to-end by using your fork of nixos-hardware and
  importing it via <nixos-hardware> or Flake input

[Kiskae]

The intel-ocl package is unfree and not required for newer processors, should it be gated behind an unfree/legacy option?

[Mic92]

The intel-ocl package is unfree and not required for newer processors, should it be gated behind an unfree/legacy option?

How old? hardware.enableRedistributableFirmware could be used potentially used if the license allows for redistribution.

[Mic92]

Potentially makes sense to have the opencl option in nixos itself: NixOS/nixpkgs#219657

[Mic92]

Suggested change

	options.hardware.intel.opencl.enable = lib.mkEnableOption (lib.mkDoc
	options.hardware.intel.opencl.enable = lib.mkEnableOption (lib.mdDoc

[Pandapip1]

Also, the module name is now hardware.intelgpu, not hardware.intel.

[Kiskae]

The intel-ocl package is unfree and not required for newer processors, should it be gated behind an unfree/legacy option?

How old? hardware.enableRedistributableFirmware could be used potentially used if the license allows for redistribution.

Both the intel-media-driver and intel-compute-runtime support starts with Broadwell, aka 5th gen intel and newer. The licence does not include any provisions for redistribution.

In addition I realized that intel-ocl is a very old version of the CPU OpenCL driver. It also includes a GPU driver but that isn't actually packaged correctly.