Fixed image filter support for vmware

The vmware compute driver does not support the image filter
based on hypervisor_type. In a heterogeneous environment,
this filter attribute allows us to provision an instance
to a specific hypervisor based on the property of the
glance image. The solution is to populate the dictionary
'supported_instances' from the vmware compute driver.

Fix for bug 1131542

Change-Id: I6ebf9f0d4a17b3083f66f69f077f910552d9a951
Merge "Fixed image filter support for vmware"