dm: core: add missing prototype for ofnode_read_u64

Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h
index 2fc9fa3..92539b8 100644
--- a/include/dm/ofnode.h
+++ b/include/dm/ofnode.h
@@ -237,6 +237,16 @@
 int ofnode_read_s32_default(ofnode node, const char *propname, s32 def);
 
 /**
+ * ofnode_read_u64() - Read a 64-bit integer from a property
+ *
+ * @node:	valid node reference to read property from
+ * @propname:	name of the property to read from
+ * @outp:	place to put value (if found)
+ * @return 0 if OK, -ve on error
+ */
+int ofnode_read_u64(ofnode node, const char *propname, u64 *outp);
+
+/**
  * ofnode_read_u64_default() - Read a 64-bit integer from a property
  *
  * @ref:	valid node reference to read property from