Currently CPU topology may only be specified together with CPU model:
<cpu match='exact'>
<model>name</model>
<topology sockets='1' cores='2' threads='3'/>
</cpu>
This patch allows for CPU topology specification without the need for
also specifying CPU model:
<cpu>
<topology sockets='1' cores='2' threads='3'/>
</cpu>
'match' attribute and 'model' element are made optional with the
restriction that 'match' attribute has to be set when 'model' is
present.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>