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/misc/ent/default.nix

@@ -0,0 +1,31 @@
+{lib, stdenv, fetchurl, unzip}:
+
+stdenv.mkDerivation {
+  pname = "ent";
+  version = "1.1";
+
+  src = fetchurl {
+    url = "https://www.fourmilab.ch/random/random.zip";
+    sha256 = "1v39jlj3lzr5f99avzs2j2z6anqqd64bzm1pdf6q84a5n8nxckn1";
+  };
+
+  # Work around the "unpacker appears to have produced no directories"
+  # case that happens when the archive doesn't have a subdirectory.
+  setSourceRoot = "sourceRoot=`pwd`";
+
+  nativeBuildInputs = [ unzip ];
+
+  buildFlags = lib.optional stdenv.cc.isClang "CC=clang";
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp ent $out/bin/
+  '';
+
+  meta = with lib; {
+    description = "Pseudorandom Number Sequence Test Program";
+    homepage = "https://www.fourmilab.ch/random/";
+    platforms = platforms.all;
+    license = licenses.publicDomain;
+  };
+}