common/gpu/nvidia*: Migrate to common/gpu/nvidia/* and add non-prime

Fixes #338

common/gpu/nvidia/default.nix

@@ -0,0 +1,8 @@
+{ lib, pkgs, ... }:
+
+{
+  services.xserver.videoDrivers = lib.mkDefault [ "nvidia" ];
+  hardware.opengl.extraPackages = with pkgs; [
+    vaapiVdpau
+  ];
+}

common/gpu/nvidia/disable.nix

@@ -0,0 +1,9 @@
+{ lib, pkgs, ... }:
+
+{
+  # This runs only intel/amdgpu igpus and nvidia dgpus do not drain power.
+
+  ##### disable nvidia, very nice battery life.
+  hardware.nvidiaOptimus.disable = lib.mkDefault true;
+  boot.blacklistedKernelModules = lib.mkDefault [ "nouveau" "nvidia" ];
+}

common/gpu/nvidia/prime.nix

@@ -0,0 +1,22 @@
+{ lib, pkgs, ... }:
+
+# This creates a new 'nvidia-offload' program that runs the application passed to it on the GPU
+# As per https://nixos.wiki/wiki/Nvidia
+let
+  nvidia-offload = pkgs.writeShellScriptBin "nvidia-offload" ''
+    export __NV_PRIME_RENDER_OFFLOAD=1
+    export __NV_PRIME_RENDER_OFFLOAD_PROVIDER=NVIDIA-G0
+    export __GLX_VENDOR_LIBRARY_NAME=nvidia
+    export __VK_LAYER_NV_optimus=NVIDIA_only
+    exec "$@"
+  '';
+in {
+  imports = [ ./. ];
+
+  environment.systemPackages = [ nvidia-offload ];
+
+  hardware.nvidia.prime = {
+    offload.enable = lib.mkDefault true;
+    # Hardware should specify the bus ID for intel/nvidia devices
+  };
+}