Replace legacy ONF_MAKEDIR= globals/macros with

Change-Id: I6fd892d27fb6d387a93cf4a07c870144584f7d47
diff --git a/makefiles/virtualenv/include.mk b/makefiles/virtualenv/include.mk
index c359f12..052f959 100644
--- a/makefiles/virtualenv/include.mk
+++ b/makefiles/virtualenv/include.mk
@@ -61,8 +61,8 @@
 ##--------------------##
 ##---]  INCLUDES  [---##
 ##--------------------##
-include $(ONF_MAKEDIR)/virtualenv/requirements-txt.mk
-include $(ONF_MAKEDIR)/virtualenv/version.mk
+include $(onf-mk-dir)/virtualenv/requirements-txt.mk
+include $(onf-mk-dir)/virtualenv/version.mk
 
 # ------------------------------------------------------------------------
 # Intent: Define macro activate= to access virtualenv activation script.
@@ -110,7 +110,7 @@
 venv-activate-patched : $(venv-activate-patched)
 $(venv-activate-patched) : $(venv-activate-script)
 	$(call banner-enter,Target $@)
-	$(ONF_MAKEDIR)/virtualenv/python_310_migration.sh
+	$(onf-mk-dir)/virtualenv/python_310_migration.sh
 	touch $@
 	$(call banner-leave,Target $@)