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/metapixel/default.nix

@@ -0,0 +1,33 @@
+{ lib, stdenv, fetchFromGitHub, libpng, libjpeg, giflib, perl, pkg-config }:
+
+stdenv.mkDerivation rec {
+  pname = "metapixel";
+  version = "1.0.2";
+
+  src = fetchFromGitHub {
+    owner = "schani";
+    repo = pname;
+    rev = "98ee9daa093b6c334941242e63f90b1c2876eb4f";
+    fetchSubmodules = true;
+    sha256 = "0r7n3a6bvcxkbpda4mwmrpicii09iql5z69nkjqygkwxw7ny3309";
+  };
+
+  makeFlags = [ "metapixel" ];
+
+  nativeBuildInputs = [ pkg-config ];
+  buildInputs = [ libpng libjpeg giflib perl ];
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp metapixel $out/bin/metapixel
+    cp metapixel-prepare $out/bin/metapixel-prepare
+    cp metapixel-sizesort $out/bin/metapixel-sizesort
+  '';
+
+  meta = with lib; {
+    homepage = "https://github.com/schani/metapixel";
+    description = "Tool for generating photomosaics";
+    license = licenses.gpl2Only;
+    maintainers = with maintainers; [ dandellion ];
+  };
+}