Add XIV/DS8K volume driver to conf ref

This driver was refactored in Havana. The patch adds a short
stub reference, pulling in the existing table, and adds it in
to the list of volume drivers.

Change-Id: I6dd7bcd564d5c05f06a7932f1be7252b15993dc5
Closes-Bug: 1213605
(cherry picked from commit d66d657abf02e030d1c12b8a6c804097c41c8065)
Merge "Add XIV/DS8K volume driver to conf ref" into stable/havana