Build: Add regression test suites out-of-tree build support

This commit support vendors to run platform-specific extra tests with
TF-M regression tests. Tf-m-tests provide a flexible interface to
integrate platform-specific tests. The platform-specific extra tests
can be included via out-of-tree build with tf-m-tests. The
out-of-tree build of extra tests can enable developers to perform
tests quickly and flexibly during development.

Signed-off-by: Jianliang Shen <jianliang.shen@arm.com>
Change-Id: Icd2a6ccc0e26acea36742b39abd72e93ab2399e2
diff --git a/test/framework/secure_suites.c b/test/framework/secure_suites.c
index b7df825..bbe3676 100644
--- a/test/framework/secure_suites.c
+++ b/test/framework/secure_suites.c
@@ -35,6 +35,9 @@
 #include "audit_s_tests.h"
 #endif
 #endif /* TFM_PSA_API */
+#ifdef EXTRA_S_TEST_SUITE
+#include "extra_s_tests.h"
+#endif
 
 static struct test_suite_t test_suites[] = {
 #ifdef TEST_S_PS
@@ -81,6 +84,12 @@
     /* Secure IPC test cases */
     {&register_testsuite_s_ipc_interface, 0, 0, 0},
 #endif
+
+#ifdef EXTRA_S_TEST_SUITE
+    /* Secure extra test cases */
+    {&register_testsuite_extra_s_interface, 0, 0, 0},
+#endif
+
     /* End of test suites */
     {0, 0, 0, 0}
 };