hw/s390/virtio-ccw: Convert to three-phase reset

hw/s390/virtio-ccw: Convert to three-phase reset

Convert the virtio-ccw code to three-phase reset.  This allows us to
remove a call to device_class_set_parent_reset(), replacing it with
the three-phase equivalent resettable_class_set_parent_phases().
Removing all the device_class_set_parent_reset() uses will allow us
to remove some of the glue code that interworks between three-phase
and legacy reset.

This is a simple conversion, with no behavioural changes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240830145812.1967042-3-peter.maydell@linaro.org