Add tf-m-tests repo configs

Change-Id: I412f411c2304a3f056fd8f89e1fcd3f34fac5e6f
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
diff --git a/tf-m-build-config.yaml b/tf-m-build-config.yaml
index 605a0b6..f217f49 100644
--- a/tf-m-build-config.yaml
+++ b/tf-m-build-config.yaml
@@ -96,6 +96,12 @@
           name: 'CMSIS_VERSION'
           default: '5.5.0'
       - string:
+          name: 'TFM_TESTS_URL'
+          default: 'https://git.trustedfirmware.org/TF-M/tf-m-tests.git'
+      - string:
+          name: 'TFM_TESTS_REFSPEC'
+          default: 'refs/heads/master'
+      - string:
           name: 'PSA_ARCH_TESTS_URL'
           default: 'https://github.com/ARM-software/psa-arch-tests'
       - string: