Add 7.0 machine types for arm/i440fx/q35/s390x/spapr.

Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211217143948.289995-1-cohuck@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>