Getting iscsi_ip_address from cinder.conf

In the current version (2.0) of the VMAX driver, we retrieve iSCSI IP
addresses dynamically from SMI-S. However, we ran into situations where
we can't get them reliably during testing. The fix is to get this
information from cinder.conf, just like in version 1.0.

Change-Id: If474f44e99cc45592bacfdec9e1eb2fa48c41e68
Closes-Bug: #1369355
Merge "Getting iscsi_ip_address from cinder.conf"