qmp: Report QOM type name on query-cpu-definitions

The new typename attribute on query-cpu-definitions will be used
to help management software use device-list-properties to check
which properties can be set using -cpu or -global for the CPU
model.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1479320499-29818-1-git-send-email-ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>