Replace references to tests/include

Update them instead to refer to framework/include, where the contents
of tests/include have been moved.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/tests/include/test/constant_flow.h b/tests/include/test/constant_flow.h
index 2aa5a99..ceead2a 100644
--- a/tests/include/test/constant_flow.h
+++ b/tests/include/test/constant_flow.h
@@ -36,7 +36,7 @@
  * do nothing are defined for convenience.
  *
  * \note #TEST_CF_SECRET must be called directly from within a .function file,
- *       not indirectly via a macro defined under tests/include or a function
+ *       not indirectly via a macro defined under framework/include or a function
  *       under framework/src. This is because we only run Valgrind for constant
  *       flow on test suites that have greppable annotations inside them (see
  *       `skip_suites_without_constant_flow` in `tests/scripts/all.sh`).