Apply Gilles suggestion to fix the problem with make on the CI when everest is enabled, i.e. use $(THIRDPARTY_DIR) instead of a fuzz specific hack involving $(THIRDPARTY_INCLUDES)
Signed-off-by: Paul Elliott <paul.elliott@arm.com>
(Reapplying changes as one commit on top of development post codestyle change instead of rewriting old branch)
Signed-off-by: Aditya Deshpande <aditya.deshpande@arm.com>