Changed IDF branch from v5.4 to v5.1

Author: reykada

tools/config.sh

@@ -6,7 +6,7 @@ if [ -z $IDF_PATH ]; then
 fi
 
 if [ -z $IDF_BRANCH ]; then
-    IDF_BRANCH="release/v5.4"
+    IDF_BRANCH="release/v5.1"
 fi
 
 if [ -z $AR_PR_TARGET_BRANCH ]; then