qdev: trigger reset from a given device

Introduce a helper function which triggers reset from a given device.
Will be used by pci bus emulation.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/hw/qdev.c b/hw/qdev.c
index b76da07..b65b63e 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -322,6 +322,11 @@
     return 0;
 }
 
+void qdev_reset_all(DeviceState *dev)
+{
+    qdev_walk_children(dev, qdev_reset_one, qbus_reset_one, NULL);
+}
+
 void qbus_reset_all(BusState *bus)
 {
     qbus_walk_children(bus, qdev_reset_one, qbus_reset_one, NULL);