dm: core: add support for device re-parenting

In common clock framework the relation b/w parent and child clocks is
determined based on the udevice parent/child information. A clock
parent could be changed based on devices needs. In case this is happen
the functionalities for clock who's parent is changed are broken. Add
a function that reparent a device. This will be used in clk-uclass.c
to reparent a clock device.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/dm/device-internal.h b/include/dm/device-internal.h
index 5145fb4..1dcc22f 100644
--- a/include/dm/device-internal.h
+++ b/include/dm/device-internal.h
@@ -84,6 +84,15 @@
 			struct driver_info *info, struct udevice **devp);
 
 /**
+ * device_reparent: reparent the device to a new parent
+ *
+ * @dev: pointer to device to be reparented
+ * @new_parent: pointer to new parent device
+ * @return 0 if OK, -ve on error
+ */
+int device_reparent(struct udevice *dev, struct udevice *new_parent);
+
+/**
  * device_ofdata_to_platdata() - Read platform data for a device
  *
  * Read platform data for a device (typically from the device tree) so that