feat: clone tf-m-tests and tf-m-extras

The platform self-test implemented by tfm resides in
the repos added here. They are needed for the upcoming
job to run tf-m's self-test at EL3 inside bl31.

Change-Id: I855ab552fdfff9d700739d96372b2357f2156f4d
Signed-off-by: Jimmy Brisson <jimmy.brisson@arm.com>
diff --git a/script/build_package.sh b/script/build_package.sh
index 88663fc..307d793 100755
--- a/script/build_package.sh
+++ b/script/build_package.sh
@@ -503,7 +503,14 @@
 
 		emit_env "MBEDTLS_DIR" "$mbedtls_dir"
 	fi
-
+	if [ "$(get_tf_opt PLATFORM_TEST)" = "tfm-testsuite" ] &&
+	   not_upon "${TF_M_TESTS_PATH}"; then
+		emit_env "TF_M_TESTS_PATH" "$WORKSPACE/tf-m-tests"
+	fi
+	if [ "$(get_tf_opt PLATFORM_TEST)" = "tfm-testsuite" ] &&
+	   not_upon "${TF_M_EXTRAS_PATH}"; then
+		emit_env "TF_M_EXTRAS_PATH" "$WORKSPACE/tf-m-extras"
+	fi
 	if [ -f "$env_file" ]; then
 		set -a
 		source "$env_file"