target/s390x: Register CPUClass:list_cpus

target/s390x: Register CPUClass:list_cpus

Both s390_cpu_list() and s390_set_qemu_cpu_model() are
defined in cpu_models.c, move their declarations in the
related "cpu_models.h" header. Use full path to header
in s390-virtio-ccw.c file.

Register s390_cpu_list() as CPUClass:list_cpus callback
and remove the cpu_list definition.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20250324185837.46506-6-philmd@linaro.org>