Qnx: Improved layout of BlackBerryDeviceConfigurationWidget

Widget margins has been zeroed so the default margins of
the 'Type Specific' group applies only. Request and Upload buttons
has been placed on a separate row to allow better width stretching.

Task-number: QTCREATORBUG-9981

Change-Id: I86d3be06d0057e92289fe6ed5cf38f16f5f3158b
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Reviewed-by: David Kaspar <dkaspar@blackberry.com>