i386: Make "max" model not use any host CPUID info on TCG

Instead of reporting host CPUID data on "max", use the qemu64 CPU
model as reference to initialize CPUID
vendor/family/model/stepping/model-id.

Message-Id: <20170222183919.11928-3-ehabkost@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Tested-by: Jiri Denemark <jdenemar@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>