buildroot

libpjsip: disable all bundled third party libraries

libpjsip bundles several third party libraries. In Buildroot we prefer
either not to build them or to depend on a proper package for each of
them. The current recipe disables most of them, but not all, so
disable the remaining ones.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>