Because core-capability releated features are model-specific and KVM
won't support it, remove the core-capability in CPU model to avoid the
warning message.

Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20210827064818.4698-3-chenyi.qiang@intel.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>