Move mbedtls_ct_uchar_mask_of_range function to the constant-time module

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/tests/suites/test_suite_base64.function b/tests/suites/test_suite_base64.function
index d332047..8998204 100644
--- a/tests/suites/test_suite_base64.function
+++ b/tests/suites/test_suite_base64.function
@@ -1,6 +1,8 @@
 /* BEGIN_HEADER */
 #include "mbedtls/base64.h"
 #include "base64_invasive.h"
+#include "constant_time_internal.h"
+#include "constant_time_invasive.h"
 #include <test/constant_flow.h>
 
 #if defined(MBEDTLS_TEST_HOOKS)