fixed issue with binary cleanup in fuzz programs

Signed-off-by: Ben Taylor <ben.taylor@linaro.org>
diff --git a/programs/fuzz/Makefile b/programs/fuzz/Makefile
index 3edd9e0..93dd4c9 100644
--- a/programs/fuzz/Makefile
+++ b/programs/fuzz/Makefile
@@ -44,7 +44,9 @@
 clean:
 ifndef WINDOWS
 	rm -rf $(BINARIES) *.o
+	rm -rf $(MBEDTLS_PATH)/tf-psa-crypto/programs/fuzz/*.o
 else
 	if exist *.o del /Q /F *.o
 	if exist *.exe del /Q /F *.exe
+	rm -rf $(MBEDTLS_PATH)/tf-psa-crypto/programs/fuzz/*.o
 endif