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/nix-serve.nix

@@ -0,0 +1,22 @@
+import ./make-test-python.nix ({ pkgs, ... }:
+{
+  name = "nix-serve";
+  nodes.machine = { pkgs, ... }: {
+    services.nix-serve.enable = true;
+    environment.systemPackages = [
+      pkgs.hello
+    ];
+  };
+  testScript = let
+    pkgHash = builtins.head (
+      builtins.match "${builtins.storeDir}/([^-]+).+" (toString pkgs.hello)
+    );
+  in ''
+    start_all()
+    machine.wait_for_unit("nix-serve.service")
+    machine.wait_for_open_port(5000)
+    machine.succeed(
+        "curl --fail -g http://0.0.0.0:5000/nar/${pkgHash}.nar -o /tmp/hello.nar"
+    )
+  '';
+})