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/pngcheck/default.nix

@@ -0,0 +1,35 @@
+{ lib, stdenv, fetchurl, zlib }:
+
+stdenv.mkDerivation rec {
+  pname = "pngcheck";
+  version = "3.0.2";
+
+  src = fetchurl {
+    url = "mirror://sourceforge/png-mng/pngcheck-${version}.tar.gz";
+    sha256 = "sha256-DX4mLyQRb93yhHqM61yS2fXybvtC6f/2PsK7dnYTHKc=";
+  };
+
+  hardeningDisable = [ "format" ];
+
+  postPatch = lib.optionalString stdenv.isDarwin ''
+    substituteInPlace Makefile.unx --replace "gcc" "clang"
+  '';
+
+  makefile = "Makefile.unx";
+  makeFlags = [ "ZPATH=${zlib.static}/lib" ];
+
+  buildInputs = [ zlib ];
+
+  installPhase = ''
+    mkdir -p $out/bin/
+    cp pngcheck $out/bin/pngcheck
+  '';
+
+  meta = with lib; {
+    homepage = "http://pmt.sourceforge.net/pngcrush";
+    description = "Verifies the integrity of PNG, JNG and MNG files";
+    license = licenses.free;
+    platforms = platforms.unix;
+    maintainers = with maintainers; [ starcraft66 ];
+  };
+}