One of the main reasons for introducing host-model CPU definition in a
domain capabilities XML was the inability to express disabled features
in a host capabilities XML. That is, when a host CPU is, e.g., Haswell
without x2apic support, host capabilities XML will have to report it as
Westmere + a bunch of additional features., but we really want to use
Haswell - x2apic when creating a host-model CPU.

Unfortunately, I somehow forgot to do the last step and the code would
just copy the CPU definition found in the host capabilities XML. This
changed recently for new QEMU versions which allow us to query host CPU,
but any slightly older QEMU will not benefit from any change I did. This
patch makes sure the right CPU model is filled in the domain
capabilities even with old QEMU.

The issue was reported in
https://bugzilla.redhat.com/show_bug.cgi?id=1426456Signed-off-by: NJiri Denemark <jdenemar@redhat.com>