Adding api set_node_ptc_num to rr_graph_builder.h

Author: Muhammad Haris Zafar

vpr/src/device/rr_graph_builder.h

@@ -80,6 +80,10 @@ class RRGraphBuilder {
     inline void set_node_class_num(RRNodeId id, short new_class_num) {
         node_storage_.set_node_class_num(id, new_class_num);
     }
+
+    inline void set_node_ptc_num(RRNodeId id, short new_ptc_num) {
+        node_storage_.set_node_ptc_num(id, new_ptc_num);
+    }
     /* -- Internal data storage -- */
   private:
     /* TODO: When the refactoring effort finishes,