tests: rewrite host CPU mocking
    
    Move all the host CPU data into a separate file and rewrite qemucpumock
    to not use passed @caps.  This is preparation for following patch which
    will replace virCaps argument with virArch.
    
    Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
    Reviewed-by: Jiri Denemark <jdenemar@redhat.com>