target/i386: Add CPU model versions supporting 'xsaves'

target/i386: Add CPU model versions supporting 'xsaves'

Hyper-V 2016 refuses to boot on Skylake+ CPU models because they lack
'xsaves'/'vmx-xsaves' features and this diverges from real hardware. The
same issue emerges with AMD "EPYC" CPU model prior to version 3 which got
'xsaves' added. EPYC-Rome/EPYC-Milan CPU models have 'xsaves' enabled from
the very beginning so the comment blaming KVM to explain why other CPUs
lack 'xsaves' is likely outdated.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210412073952.860944-1-vkuznets@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>