vty: move struct vty_parent_node to private API

Change-Id: Id2070f03b09feea966c5342361d409551e557d38
diff --git a/src/vty/command.c b/src/vty/command.c
index a60b544..e67fd86 100644
--- a/src/vty/command.c
+++ b/src/vty/command.c
@@ -77,6 +77,21 @@
 /* Host information structure. */
 struct host host;
 
+struct vty_parent_node {
+	struct llist_head entry;
+
+	/*! private data, specified by creator */
+	void *priv;
+	void *index;
+
+	/*! Node status of this vty */
+	int node;
+
+	/*! When reading from a config file, these are the indenting characters expected for children of
+	 * this VTY node. */
+	char *indent;
+};
+
 /* Standard command node structures. */
 struct cmd_node auth_node = {
 	AUTH_NODE,