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/image-contents.nix

@@ -0,0 +1,51 @@
+# Tests the contents attribute of nixos/lib/make-disk-image.nix
+# including its user, group, and mode attributes.
+{ system ? builtins.currentSystem,
+  config ? {},
+  pkgs ? import ../.. { inherit system config; }
+}:
+
+with import ../lib/testing-python.nix { inherit system pkgs; };
+with pkgs.lib;
+
+with import common/ec2.nix { inherit makeTest pkgs; };
+
+let
+  config = (import ../lib/eval-config.nix {
+    inherit system;
+    modules = [
+      ../modules/testing/test-instrumentation.nix
+      ../modules/profiles/qemu-guest.nix
+      {
+        fileSystems."/".device = "/dev/disk/by-label/nixos";
+        boot.loader.grub.device = "/dev/vda";
+        boot.loader.timeout = 0;
+      }
+    ];
+  }).config;
+  image = (import ../lib/make-disk-image.nix {
+    inherit pkgs config;
+    lib = pkgs.lib;
+    format = "qcow2";
+    contents = [{
+      source = pkgs.writeText "testFile" "contents";
+      target = "/testFile";
+      user = "1234";
+      group = "5678";
+      mode = "755";
+    }];
+  }) + "/nixos.qcow2";
+
+in makeEc2Test {
+  name = "image-contents";
+  inherit image;
+  userData = null;
+  script = ''
+    machine.start()
+    assert "content" in machine.succeed("cat /testFile")
+    fileDetails = machine.succeed("ls -l /testFile")
+    assert "1234" in fileDetails
+    assert "5678" in fileDetails
+    assert "rwxr-xr-x" in fileDetails
+  '';
+}