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/nix/nixdoc/default.nix

@@ -0,0 +1,25 @@
+{ lib, stdenv, fetchFromGitHub, rustPlatform, darwin }:
+
+rustPlatform.buildRustPackage rec {
+  pname = "nixdoc";
+  version = "1.0.1";
+
+  src = fetchFromGitHub {
+    owner = "tazjin";
+    repo  = "nixdoc";
+    rev = "v${version}";
+    sha256 = "14d4dq06jdqazxvv7fq5872zy0capxyb0fdkp8qg06gxl1iw201s";
+  };
+
+  buildInputs =  lib.optionals stdenv.isDarwin [ darwin.Security ];
+
+  cargoSha256 = "1nv6g8rmjjbwqmjkrpqncypqvx5c7xp2zlx5h6rw2j9d1wlys0v5";
+
+  meta = with lib; {
+    description = "Generate documentation for Nix functions";
+    homepage    = "https://github.com/tazjin/nixdoc";
+    license     = [ licenses.gpl3 ];
+    maintainers = [ maintainers.tazjin ];
+    platforms   = platforms.unix;
+  };
+}