BlackBerry: Add a private PPS API

The PPS API is needed to implement other Qt APIs on BlackBerry.
It is a private API that cannot be accessed from outside Qt (*_p).

Change-Id: Id33d2f9a415f49d51812ae860a15e8cc5636676b
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>
Reviewed-by: Rafael Roquetto <rafael.roquetto@kdab.com>