Build: Update tf-m-tests commit ID

To include two reference SFN partitions.

Change-Id: I911054762e38a5e8dab6aa19738f42befa2f5953
Signed-off-by: Ken Liu <Ken.Liu@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 f4d0968..f45f35c 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               "92fe758"   CACHE STRING    "The version of tf-m-tests to use")
+set(TFM_TEST_REPO_VERSION               "7f8f704"   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")