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/development/ocaml-modules/tar/unix.nix

@@ -0,0 +1,27 @@
+{ lib
+, buildDunePackage
+, tar
+, cstruct
+, cstruct-lwt
+, re
+, lwt
+}:
+
+buildDunePackage rec {
+  pname = "tar-unix";
+  inherit (tar) version src useDune2 doCheck;
+
+  propagatedBuildInputs = [
+    tar
+    cstruct
+    cstruct-lwt
+    re
+    lwt
+  ];
+
+  meta = {
+    description = "Decode and encode tar format files from Unix";
+    license = lib.licenses.mit;
+    maintainers = [ lib.maintainers.ulrikstrid ];
+  };
+}