hw: add compat machines for 5.2

Add 5.2 machine types for arm/i440fx/q35/s390x/spapr.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200819144016.281156-1-cohuck@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>