Merge remote-tracking branch 'afaerber-or/qom-next-2' into staging

* afaerber-or/qom-next-2: (22 commits)
  qom: Push error reporting to object_property_find()
  qdev: Remove qdev_prop_exists()
  qbus: Initialize in standard way
  qbus: Make child devices links
  qdev: Connect busses with their parent devices
  qdev: Convert busses to QEMU Object Model
  qdev: Move SysBus initialization to sysbus.c
  qdev: Use wrapper for qdev_get_path
  qdev: Remove qdev_prop_set_defaults
  qdev: Clean up global properties
  qdev: Move bus properties to abstract superclasses
  qdev: Move bus properties to a separate global
  qdev: Push "type" property up to Object
  arm_l2x0: Rename "type" property to "cache-type"
  m48t59: Rename "type" property to "model"
  qom: Assert that public types have a non-NULL parent field
  qom: Drop type_register_static_alias() macro
  qom: Make Object a type
  qom: Add class_base_init
  qom: Add object_child_foreach()
  ...