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/app.nix

@@ -0,0 +1,48 @@
+{ lib
+, buildDunePackage
+, letsencrypt
+, letsencrypt-dns
+, cmdliner
+, cohttp-lwt-unix
+, logs
+, fmt
+, lwt
+, mirage-crypto-rng
+, ptime
+, bos
+, fpath
+, randomconv
+, cstruct
+}:
+
+buildDunePackage {
+  pname = "letsencrypt-app";
+
+  inherit (letsencrypt)
+    src
+    version
+    useDune2
+    minimumOCamlVersion
+    ;
+
+  buildInputs = [
+    letsencrypt
+    letsencrypt-dns
+    cmdliner
+    cohttp-lwt-unix
+    logs
+    fmt
+    lwt
+    mirage-crypto-rng
+    ptime
+    bos
+    fpath
+    randomconv
+    cstruct
+  ];
+
+  meta = letsencrypt.meta // {
+    description = "An ACME client implementation of the ACME protocol (RFC 8555) for OCaml";
+    mainProgram = "oacmel";
+  };
+}