Change iogrp property when retyping for Storwize/SVC

Change iogrp property when retyping for Storwize/SVC

If need migration when retyping, Storwize/SVC driver will add a copy
of the volume first, and then start a task to check volume sync
progress which will run each 10 mins. At last delete the origin copy
when sync finished.

But iogrp property is not a parameter of addvdiskcopy, so the iogrp
of the copy volume is the same as the origin. If iogrp property is
diff between the old and new volume type, the property will not
change when retyped.

Change-Id: Ie4414bcf95fa6e61d7d618618f48837eef740da4
closed-bug: #1298247
(cherry picked from commit 5c336123d3252e7fc4e1aeabd853457ab05838be)