complibs/cloog: remove old CLooG/PPL versions

Those versions are no longer available upstream. They have purely and
simply disapeared, without leaving any trace of their mere existences.

Just keep the latest cloog-ppl-0.15.11, which still exists on the gcc
infra mirror (but for how long?)

Reported-by: Guillaume FLORENCE-COURTAND <gflorenc@laposte.net>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 reporter_name="Kevin Cernekee"

 reporter_url="http://sourceware.org/ml/crossgcc/2011-09/msg00037.html"

 reporter_comment="MIPS SDE-compatible toolchain"