Add opt-testcases into check list

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/tests/scripts/check_test_cases.py b/tests/scripts/check_test_cases.py
index fe11f20..f9ae36c 100755
--- a/tests/scripts/check_test_cases.py
+++ b/tests/scripts/check_test_cases.py
@@ -133,6 +133,9 @@
             ssl_opt_sh = os.path.join(directory, 'ssl-opt.sh')
             if os.path.exists(ssl_opt_sh):
                 self.walk_ssl_opt_sh(ssl_opt_sh)
+            for ssl_opt_file_name in glob.glob(os.path.join(directory, 'opt-testcases',
+                                                            '*.sh')):
+                self.walk_ssl_opt_sh(ssl_opt_file_name)
 
 class DescriptionChecker(TestDescriptionExplorer):
     """Check all test case descriptions.