Build: Update tf-m-tests commit ID

Signed-off-by: Jianliang Shen <jianliang.shen@arm.com>
Change-Id: Ia3eff3a68e783e8e4f8c3b5f45c65567b41b10cf
diff --git a/lib/ext/tf-m-tests/repo_config_default.cmake b/lib/ext/tf-m-tests/repo_config_default.cmake
index fb164f2..f92362c 100644
--- a/lib/ext/tf-m-tests/repo_config_default.cmake
+++ b/lib/ext/tf-m-tests/repo_config_default.cmake
@@ -8,5 +8,5 @@
 # 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               "2959c1f"   CACHE STRING    "The version of tf-m-tests to use")
+set(TFM_TEST_REPO_VERSION               "7a814e4"   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")