Add cudainfo program to test CUDA

The cudainfo program checks that we can initialize the CUDA RT library
and communicate with the driver. It can be used as standalone program or
built with cudainfo.gpuCheck so it is executed inside the build sandbox
to see if it also works fine. It uses the autoAddDriverRunpath hook to
inject in the runpath the location of the library directory for CUDA
libraries.

m/module/nvidia.nix

@@ -1,4 +1,4 @@
-{ lib, config, ... }:
+{ lib, config, pkgs, ... }:
 {
   # Configure Nvidia driver to use with CUDA
   hardware.nvidia.package = config.boot.kernelPackages.nvidiaPackages.production;
@@ -15,4 +15,6 @@
   programs.nix-required-mounts.allowedPatterns.nvidia-gpu.paths = [
     config.systemd.tmpfiles.settings.graphics-driver."/run/opengl-driver"."L+".argument
   ];
+
+  environment.systemPackages = [ pkgs.cudainfo ];
 }