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/applications/misc/prevo/tools.nix

@@ -0,0 +1,38 @@
+{ lib, stdenv, fetchFromGitHub, autoreconfHook, pkg-config, glib, expat
+, installShellFiles }:
+
+stdenv.mkDerivation rec {
+  pname = "prevo-tools";
+  version = "0.2";
+
+  src = fetchFromGitHub {
+    owner = "bpeel";
+    repo = "prevodb";
+    rev = version;
+    sha256 = "1fyrc4g9qdq04nxs4g8x0krxfani5xady6v9m0qfqpbh4xk2ry2d";
+  };
+
+  nativeBuildInputs = [ autoreconfHook pkg-config installShellFiles ];
+  buildInputs = [ glib expat ];
+
+  postInstall = ''
+    installShellCompletion --bash src/prevo-completion
+  '';
+
+  meta = with lib; {
+    description =
+      "CLI tools for the offline version of the Esperanto dictionary Reta Vortaro";
+    longDescription = ''
+      PReVo is the "portable" ReVo, i.e., the offline version
+      of the Esperanto dictionary Reta Vortaro.
+
+      This package provides the command line application prevo to query a local
+      ReVo database, as well as the command line tool revodb to create such a
+      database for this application or for the Android app of the same name.
+    '';
+    homepage = "https://github.com/bpeel/prevodb";
+    license = licenses.gpl2Only;
+    maintainers = [ maintainers.das-g ];
+    platforms = platforms.linux;
+  };
+}