uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

nixos/modules/services/hardware/nvidia-optimus.nix

@@ -0,0 +1,43 @@
+{ config, lib, ... }:
+
+let kernel = config.boot.kernelPackages; in
+
+{
+
+  ###### interface
+
+  options = {
+
+    hardware.nvidiaOptimus.disable = lib.mkOption {
+      default = false;
+      type = lib.types.bool;
+      description = ''
+        Completely disable the NVIDIA graphics card and use the
+        integrated graphics processor instead.
+      '';
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = lib.mkIf config.hardware.nvidiaOptimus.disable {
+    boot.blacklistedKernelModules = ["nouveau" "nvidia" "nvidiafb" "nvidia-drm"];
+    boot.kernelModules = [ "bbswitch" ];
+    boot.extraModulePackages = [ kernel.bbswitch ];
+
+    systemd.services.bbswitch = {
+      description = "Disable NVIDIA Card";
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+        ExecStart = "${kernel.bbswitch}/bin/discrete_vga_poweroff";
+        ExecStop = "${kernel.bbswitch}/bin/discrete_vga_poweron";
+      };
+      path = [ kernel.bbswitch ];
+    };
+  };
+
+}