Fixed build issue on BlackBerry

BlackBerry build was missing QTzTimeZonePrivate implementation.

Change-Id: Ieaf6148a67c66f330e846c93f829ca17a4494359
Reviewed-by: Mehdi Fekari <mfekari@blackberry.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Wolfgang Bremer <wbremer@blackberry.com>