nixos/intel-gpu: Add support for intel iGPUs

Might need to be adapted if used on ARC or really old iGPUs. See nixos
documentation

modules/system-settings/intel-gpu.nix

@@ -0,0 +1,15 @@
+{
+	flake.modules.nixos.intel-gpu = {pkgs, ...}: {
+		boot.kernelModules = [ "kvm-intel" ];
+
+		hardware.graphics = {
+			enable = true;
+			extraPackages = with pkgs; [
+				intel-media-driver
+				intel-compute-runtime
+			];
+		};
+
+		environment.sessionVariables.LIBVA_DRIVER_NAME = "iHD";
+	};
+}