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/letsencrypt/dns.nix

@@ -0,0 +1,35 @@
+{ lib
+, buildDunePackage
+, letsencrypt
+, logs
+, fmt
+, lwt
+, dns
+, dns-tsig
+, domain-name
+}:
+
+buildDunePackage {
+  pname = "letsencrypt-dns";
+
+  inherit (letsencrypt)
+    version
+    src
+    useDune2
+    minimumOCamlVersion
+    ;
+
+  propagatedBuildInputs = [
+    letsencrypt
+    dns
+    dns-tsig
+    domain-name
+    logs
+    lwt
+    fmt
+  ];
+
+  meta = letsencrypt.meta // {
+    description = "A DNS solver for the ACME implementation in OCaml";
+  };
+}