Improve IBM Storage driver description

Enhance description, add references, add additional values that need to
be set.

Change-Id: Ie72d50e5efc3b7ef4e0083563ce02e379b997b19
Co-Authored-By: Alon Marx <alonma@il.ibm.com>
Closes-Bug: #1347523
Merge "Improve IBM Storage driver description"