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>

pkgs/test/nixos-functions/default.nix

@@ -0,0 +1,31 @@
+/*
+
+This file is a test that makes sure that the `pkgs.nixos` and
+`pkgs.testers.nixosTest` functions work. It's far from a perfect test suite,
+but better than not checking them at all on hydra.
+
+To run this test:
+
+    nixpkgs$ nix-build -A tests.nixos-functions
+
+ */
+{ pkgs, lib, stdenv, ... }:
+
+let
+  dummyVersioning = {
+    revision = "test";
+    versionSuffix = "test";
+    label = "test";
+  };
+in lib.optionalAttrs stdenv.hostPlatform.isLinux (
+  pkgs.recurseIntoAttrs {
+
+    nixos-test = (pkgs.nixos {
+      system.nixos = dummyVersioning;
+      boot.loader.grub.enable = false;
+      fileSystems."/".device = "/dev/null";
+      system.stateVersion = lib.trivial.release;
+    }).toplevel;
+
+  }
+)