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/development/tools/ronn/default.nix

@@ -0,0 +1,39 @@
+{ stdenv, lib, bundlerEnv, bundlerUpdateScript, makeWrapper, groff, callPackage }:
+
+stdenv.mkDerivation rec {
+  pname = "ronn";
+  version = env.gems.ronn-ng.version;
+
+  env = bundlerEnv {
+    name = "ronn-gems";
+    gemdir = ./.;
+  };
+
+  dontUnpack = true;
+
+  nativeBuildInputs = [
+    makeWrapper
+  ];
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/bin
+    makeWrapper ${env}/bin/ronn $out/bin/ronn \
+      --set PATH ${groff}/bin
+
+    runHook postInstall
+  '';
+
+  passthru.updateScript = bundlerUpdateScript "ronn";
+
+  passthru.tests.reproducible-html-manpage = callPackage ./test-reproducible-html.nix { };
+
+  meta = with lib; {
+    description = "markdown-based tool for building manpages";
+    homepage = "https://github.com/apjanke/ronn-ng";
+    license = licenses.mit;
+    maintainers = with maintainers; [ zimbatm nicknovitski ];
+    platforms = env.ruby.meta.platforms;
+  };
+}