Test Framework: Move start test functions into test suites

The test framework should not be responsible on how to start
particular test suites.
It only needs to provides a general run_test() API (already have).

Move the functions which start test suites to corresponding test
suites code.

Change-Id: I62fc17ae8bf75dd7f8b8d44d78382d82d369aabb
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
diff --git a/tests_reg/test_app.c b/tests_reg/test_app.c
index d29743c..35b07d3 100644
--- a/tests_reg/test_app.c
+++ b/tests_reg/test_app.c
@@ -8,7 +8,7 @@
 #include "test_app.h"
 #include "tfm_log.h"
 #ifdef TFM_NS_REG_TEST
-#include "test_framework_integ_test.h"
+#include "non_secure_suites.h"
 #endif
 
 /**
@@ -21,7 +21,7 @@
     UNUSED_VARIABLE(argument);
 
 #ifdef TFM_NS_REG_TEST
-    tfm_non_secure_client_run_tests();
+    ns_reg_test_start();
 #endif
 
     /* Output EOT char for test environments like FVP. */