dm: core: Correct device_get_child_by_of_offset() parameter

This parameter is named 'seq' but should be named 'of_offset'.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/dm/device.h b/include/dm/device.h
index 9a94ee1..9fa0048 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -386,7 +386,7 @@
  * @devp: Returns pointer to device if found, otherwise this is set to NULL
  * @return 0 if OK, -ve on error
  */
-int device_get_child_by_of_offset(struct udevice *parent, int seq,
+int device_get_child_by_of_offset(struct udevice *parent, int of_offset,
 				  struct udevice **devp);
 
 /**