hw/s390x: Include the tod-qemu also for builds with --disable-tcg

hw/s390x: Include the tod-qemu also for builds with --disable-tcg

The device is required for running qtests, see hw/s390x/tod.c:

void s390_init_tod(void)
{
    Object *obj;

    if (kvm_enabled()) {
        obj = object_new(TYPE_KVM_S390_TOD);
    } else {
        obj = object_new(TYPE_QEMU_S390_TOD);
    }
    [...]
  }

During qtests, we're running without kvm, so TYPE_QEMU_S390_TOD is
required to avoid that QEMU aborts here.

Fixes: 8046f374a6 ("s390x/tod: factor out TOD into separate device")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1539264723-741-1-git-send-email-thuth@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>