cpus: Restrict 'start-powered-off' property to system emulation

Since the CPUState::start-powered-off property is irrelevant
to user emulation, restrict it to system emulation.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240111161817.43150-1-philmd@linaro.org>

cpu-target.c

@@ -204,6 +204,7 @@ static Property cpu_common_props[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
+#ifndef CONFIG_USER_ONLY
 static bool cpu_get_start_powered_off(Object *obj, Error **errp)
 {
     CPUState *cpu = CPU(obj);
@@ -215,19 +216,23 @@ static void cpu_set_start_powered_off(Object *obj, bool value, Error **errp)
     CPUState *cpu = CPU(obj);
     cpu->start_powered_off = value;
 }
+#endif
 
 void cpu_class_init_props(DeviceClass *dc)
 {
+#ifndef CONFIG_USER_ONLY
     ObjectClass *oc = OBJECT_CLASS(dc);
 
-    device_class_set_props(dc, cpu_common_props);
     /*
      * We can't use DEFINE_PROP_BOOL in the Property array for this
      * property, because we want this to be settable after realize.
      */
     object_class_property_add_bool(oc, "start-powered-off",
                                    cpu_get_start_powered_off,
                                    cpu_set_start_powered_off);
+#endif
+
+    device_class_set_props(dc, cpu_common_props);
 }
 
 void cpu_exec_initfn(CPUState *cpu)