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/libraries/libxmlxx/v3.nix

@@ -0,0 +1,41 @@
+{ lib, stdenv, fetchurl, pkg-config, libxml2, glibmm, perl, gnome }:
+
+stdenv.mkDerivation rec {
+  pname = "libxml++";
+  version = "3.0.1";
+
+  src = fetchurl {
+    url = "mirror://gnome/sources/libxml++/${lib.versions.majorMinor version}/${pname}-${version}.tar.xz";
+    sha256 = "19kik79fmg61nv0by0a5f9wchrcfjwzvih4v2waw01hqflhqvp0r";
+  };
+
+  outputs = [ "out" "dev" "doc" "devdoc" ];
+
+  nativeBuildInputs = [ pkg-config perl ];
+
+  buildInputs = [ glibmm ];
+
+  propagatedBuildInputs = [ libxml2 ];
+
+  postFixup = ''
+    substituteInPlace $dev/lib/pkgconfig/libxml++-3.0.pc \
+      --replace 'docdir=''${datarootdir}' "docdir=$doc/share"
+  '';
+
+  passthru = {
+    updateScript = gnome.updateScript {
+      attrPath = "libxmlxx3";
+      packageName = pname;
+      versionPolicy = "odd-unstable";
+      freeze = true;
+    };
+  };
+
+  meta = with lib; {
+    homepage = "http://libxmlplusplus.sourceforge.net/";
+    description = "C++ wrapper for the libxml2 XML parser library, version 3";
+    license = licenses.lgpl2Plus;
+    platforms = platforms.unix;
+    maintainers = with maintainers; [ loskutov ];
+  };
+}