hw/core/qdev-properties: Constify Property argument to object_field_prop_ptr

This logically should have accompanied d36f165d952 which
allowed const Property to be registered.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Lei Yang <leiyang@redhat.com>
Link: https://lore.kernel.org/r/20241218134251.4724-23-richard.henderson@linaro.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/core/qdev-properties.c

@@ -51,7 +51,7 @@ void qdev_prop_allow_set_link_before_realize(const Object *obj,
     }
 }
 
-void *object_field_prop_ptr(Object *obj, Property *prop)
+void *object_field_prop_ptr(Object *obj, const Property *prop)
 {
     void *ptr = obj;
     ptr += prop->offset;

include/hw/qdev-properties.h

@@ -201,7 +201,7 @@ void qdev_prop_set_enum(DeviceState *dev, const char *name, int value);
 /* Takes ownership of @values */
 void qdev_prop_set_array(DeviceState *dev, const char *name, QList *values);
 
-void *object_field_prop_ptr(Object *obj, Property *prop);
+void *object_field_prop_ptr(Object *obj, const Property *prop);
 
 void qdev_prop_register_global(GlobalProperty *prop);
 const GlobalProperty *qdev_find_global_prop(Object *obj,