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/tests/atd.nix

@@ -0,0 +1,31 @@
+import ./make-test-python.nix ({ pkgs, ... }:
+
+{
+  name = "atd";
+  meta = with pkgs.lib.maintainers; {
+    maintainers = [ bjornfor ];
+  };
+
+  nodes.machine =
+    { ... }:
+    { services.atd.enable = true;
+      users.users.alice = { isNormalUser = true; };
+    };
+
+  # "at" has a resolution of 1 minute
+  testScript = ''
+    start_all()
+
+    machine.wait_for_unit("atd.service")  # wait for atd to start
+    machine.fail("test -f ~root/at-1")
+    machine.fail("test -f ~alice/at-1")
+
+    machine.succeed("echo 'touch ~root/at-1' | at now+1min")
+    machine.succeed("su - alice -c \"echo 'touch at-1' | at now+1min\"")
+
+    machine.succeed("sleep 1.5m")
+
+    machine.succeed("test -f ~root/at-1")
+    machine.succeed("test -f ~alice/at-1")
+  '';
+})