Remove all submodules, hipos-testing and management info files.

That equals to removing everything that is _not_ meta-hipos.

Signed-off-by: Angelika Tobisch <tobisch@dresearch-fe.de>
move meta-hipos to top level

This is in preparation for making it a submodule.

Signed-off-by: Angelika Tobisch <tobisch@dresearch-fe.de>