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/tools/text/dirdiff/default.nix

@@ -0,0 +1,59 @@
+{ copyDesktopItems, fetchurl, lib, makeDesktopItem, stdenv, tcl, tk }:
+
+stdenv.mkDerivation rec {
+  pname = "dirdiff";
+  version = "2.1";
+
+  src = fetchurl {
+    url = "mirror://samba/paulus/${pname}-${version}.tar.gz";
+    sha256 = "0lljd8av68j70733yshzzhxjr1lm0vgmbqsm8f02g03qsma3cdyb";
+  };
+
+  nativeBuildInputs = [ copyDesktopItems ];
+  buildInputs = [ tcl tk ];
+
+  # Some light path patching.
+  patches = [ ./dirdiff-2.1-vars.patch ];
+  postPatch = ''
+    for file in dirdiff Makefile; do
+      substituteInPlace "$file" \
+          --subst-var out \
+          --subst-var-by tcl ${tcl} \
+          --subst-var-by tk ${tk}
+    done
+  '';
+
+  # If we don't create the directories ourselves, then 'make install' creates
+  # files named 'bin' and 'lib'.
+  preInstall = ''
+    mkdir -p $out/bin $out/lib
+  '';
+
+  installFlags = [
+    "BINDIR=${placeholder "out"}/bin"
+    "LIBDIR=${placeholder "out"}/lib"
+  ];
+
+  desktopItems = [
+    (makeDesktopItem {
+      name = "dirdiff";
+      exec = "dirdiff";
+      desktopName = "Dirdiff";
+      genericName = "Directory Diff Viewer";
+      comment = "Diff and merge directory trees";
+      categories = [ "Development" ];
+    })
+  ];
+
+  meta = with lib; {
+    description = "Graphical directory tree diff and merge tool";
+    longDescription = ''
+      Dirdiff is a graphical tool for displaying the differences between
+      directory trees and for merging changes from one tree into another.
+    '';
+    homepage = "https://www.samba.org/ftp/paulus/";
+    license = licenses.gpl2Plus;
+    maintainers = with maintainers; [ khumba ];
+    platforms = platforms.linux;
+  };
+}