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/graphics/optipng/default.nix

@@ -0,0 +1,44 @@
+{ lib, stdenv, fetchurl, libpng
+, static ? stdenv.hostPlatform.isStatic
+}:
+
+# This package comes with its own copy of zlib, libpng and pngxtern
+
+with lib;
+
+stdenv.mkDerivation rec {
+  pname = "optipng";
+  version = "0.7.7";
+
+  src = fetchurl {
+    url = "mirror://sourceforge/optipng/optipng-${version}.tar.gz";
+    sha256 = "0lj4clb851fzpaq446wgj0sfy922zs5l5misbpwv6w7qrqrz4cjg";
+  };
+
+  buildInputs = [ libpng ];
+
+  LDFLAGS = optional static "-static";
+  # Workaround for crash in cexcept.h. See
+  # https://github.com/NixOS/nixpkgs/issues/28106
+  preConfigure = ''
+    export LD=$CC
+  '';
+
+  configureFlags = [
+    "--with-system-zlib"
+    "--with-system-libpng"
+  ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
+    #"-prefix=$out"
+  ];
+
+  postInstall = if stdenv.hostPlatform != stdenv.buildPlatform && stdenv.hostPlatform.isWindows then ''
+    mv "$out"/bin/optipng{,.exe}
+  '' else null;
+
+  meta = with lib; {
+    homepage = "http://optipng.sourceforge.net/";
+    description = "A PNG optimizer";
+    license = licenses.zlib;
+    platforms = platforms.unix;
+  };
+}