Build: Update test repo version

Change-Id: I6ab333524904f392693c83f51a74e21e40d58d2b
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
diff --git a/lib/ext/tf-m-tests/repo_config_default.cmake b/lib/ext/tf-m-tests/repo_config_default.cmake
index 49b1440..3b3e21a 100644
--- a/lib/ext/tf-m-tests/repo_config_default.cmake
+++ b/lib/ext/tf-m-tests/repo_config_default.cmake
@@ -10,5 +10,5 @@
 # Default configs of tf-m-tests repo
 
 set(TFM_TEST_REPO_PATH                  "DOWNLOAD"  CACHE PATH      "Path to TFM-TEST repo (or DOWNLOAD to fetch automatically")
-set(TFM_TEST_REPO_VERSION               "21a4421d"  CACHE STRING    "The version of tf-m-tests to use")
+set(TFM_TEST_REPO_VERSION               "bb479b1"   CACHE STRING    "The version of tf-m-tests to use")
 set(CMSIS_5_PATH                        "DOWNLOAD"  CACHE PATH      "Path to CMSIS_5 (or DOWNLOAD to fetch automatically")