hw/smbios: Use qapi for SmbiosEntryPointType

hw/smbios: Use qapi for SmbiosEntryPointType

This prepares for exposing the SMBIOS entry point type as a
machine property on x86.

Based on a patch from Daniel P. Berrangé.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20211026151100.1691925-3-ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>