dependencies/cmake: blacklist cmake 3.7

cmake-3.7 has a bug in how it handles rpath, linking with libraries from
the host.

Until we completely understand the issue, just blacklist cmake-3.7.

The issue has been reported upstream:
    http://public.kitware.com/pipermail/cmake/2017-February/064970.html



Reported-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Jörg Krause <joerg.krause@embedded.rocks>
Cc: Ben Boeckel <mathstuf@gmail.com>
Cc: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>