hw/i386/pc: Default to use SMBIOS 3.0 for newer machine models

hw/i386/pc: Default to use SMBIOS 3.0 for newer machine models

Currently, pc-q35 and pc-i44fx machine models are default to use SMBIOS 2.8
(32-bit entry point). Since SMBIOS 3.0 (64-bit entry point) is now fully
supported since QEMU 7.0, default to use SMBIOS 3.0 for newer machine
models. This is necessary to avoid the following message when launching
a VM with large number of vcpus.

   "SMBIOS 2.1 table length 66822 exceeds 65535"

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20230607205717.737749-2-suravee.suthikulpanit@amd.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>