Resolve conflicting mac address in resize

This patch fixes bug 1161226 and mac address conflicts when migrating or
resizing an instance using the PowerVM driver. This will ensure that if
a migration or resize is taking place on the same host, a temporary mac
address will be assigned to the original LPAR so there is no conflict on
the VIOS when a second LPAR is started with the same address.

Change-Id: I59db484defb789f3a7c0eddbd5ef9e92efc22419
Merge "Resolve conflicting mac address in resize"