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/compression/gzrt/default.nix

@@ -0,0 +1,27 @@
+{ lib, stdenv, fetchurl, zlib }:
+
+stdenv.mkDerivation rec {
+  pname = "gzrt";
+  version = "0.8";
+
+  src = fetchurl {
+    url = "https://www.urbanophile.com/arenn/coding/gzrt/gzrt-${version}.tar.gz";
+    sha256 = "1vhzazj47xfpbfhzkwalz27cc0n5gazddmj3kynhk0yxv99xrdxh";
+  };
+
+  buildInputs = [ zlib ];
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp gzrecover $out/bin
+  '';
+
+  meta = with lib; {
+    homepage = "https://www.urbanophile.com/arenn/hacking/gzrt/";
+    description = "The gzip Recovery Toolkit";
+    maintainers = with maintainers; [ ];
+    mainProgram = "gzrecover";
+    license = licenses.gpl2Plus;
+    platforms = platforms.unix;
+  };
+}