x86: svm: run svm.flat unit tests with -cpu host

With -cpu qemu64 we skip many good tests (next_rip, npt_*) and
tsc_adjust is failing. VMX tests already use '-cpu host'.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20191008163829.1003-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>