Wi-sun certification test setup update

Updated selected parent to 4 which force to generate all 8 possible neighbour candidate use.

Change-Id: I4e634a8c9117a535236b378d9ccf5bad53b849c8

Author: Juha Heiskanen

source/6LoWPAN/ws/ws_common_defines.h

@@ -211,7 +211,7 @@ typedef struct ws_bs_ie {
 #define WS_RPL_SELECTED_PARENT_MAX 2
 
 #define WS_CERTIFICATE_RPL_PARENT_CANDIDATE_MAX 8
-#define WS_CERTIFICATE_RPL_SELECTED_PARENT_MAX 3
+#define WS_CERTIFICATE_RPL_SELECTED_PARENT_MAX 4
 
 /**
  * Wi-sun spesific non-preferred prefix policy label