dev-lang/ocaml: Version bump to 4.02.1

The libraries Camlp4 and LablTk are not shipped with the OCaml standard
distribution anymore; as such, they are now packaged in dev-ocaml/{camlp4,labltk}
and the relevant options were dropped from dev-lang/ocaml

Change-Id: I53d9d749c2e5d4d1770b1d856be03eb29ae0993a