acf-provisioning: add suport for VVX phones
The latest software for VVX: http://support.polycom.com/PolycomService/support/us/support/voice/polycom\_uc/polycom\_uc\_software\_release.html\#5.3.0
(from redmine: issue id 4170, created on 2015-05-11, closed on 2015-06-02)