virt: Highlight soon-to-be-unused driver APIs
virt: Highlight soon-to-be-unused driver APIs

These are all XenAPI-only APIs and can be removed in the near future
when that driver goes away. Highlight this fact now.

Change-Id: I04f6bd4000f58b9da2e4165aa2d623e795845d4e
Signed-off-by: Stephen Finucane <4725dc7f3632bf126d9fbdc30c347e91e8d2fe16@redhat.com>

mahak/nova,mahak/nova,klmitch/nova,klmitch/nova,mahak/nova,openstack/nova,openstack/nova,openstack/nova,klmitch/nova,klmitch/nova