add empty function for ws_stack_info_get

Author: Mika

source/6LoWPAN/ws/ws_empty_functions.c

@@ -406,7 +406,7 @@ void ns_time_api_system_time_callback_set(ns_time_api_system_time_callback callb
     (void) callback;
 }
 
-int ws_state_info_get(int8_t interface_id, ws_stack_info_t *info_ptr)
+int ws_stack_info_get(int8_t interface_id, ws_stack_info_t *info_ptr)
 {
     (void) interface_id;
     (void) info_ptr;