Fix evaluation. (licenses, not licences)

Thanks Domen.

pkgs/development/libraries/cl/default.nix

···
   meta = {
     homepage = https://github.com/tonyrog/cl;
     description = "OpenCL binding for Erlang";
-    license = stdenv.lib.licences.mit;
+    license = stdenv.lib.licenses.mit;
   };
 }