Edits to help support repo:onf-make as a git submodule.

transition.mk
-------------
  o Basic bridge logic for transition to repo:onf-make.
  o Include costs.mk and virtualenv targets.
  o Conditional include.mk logic to inline into Makefile
    appended at the end.

makefiles/detect
----------------
  o WIP
  o Add detection logic to enable makefile features based on extension.
  o Targets and logic can be loaded on demand based on available source.
    VS kitchen sink/load everything that happens now.

Signed-off-by: Joey Armstrong <jarmstrong@linuxfoundation.org>
Change-Id: I0d9af7bc15d7556ae7e15c5410b36189160c875d
diff --git a/makefiles/include.mk b/makefiles/include.mk
index e2a1220..ee2792d 100644
--- a/makefiles/include.mk
+++ b/makefiles/include.mk
@@ -2,7 +2,7 @@
 # -----------------------------------------------------------------------
 # Copyright 2017-2024 Open Networking Foundation (ONF) and the ONF Contributors
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
+# Licensed unde the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
@@ -50,9 +50,12 @@
 
 ONF_MAKEDIR   := $(onf-mk-dir)#   # TODO: Deprecate ONF_MAKEDIR and MAKEDIR
 
-#--------------------##
+##--------------------##
 ##---]  INCLUDES  [---##
 ##--------------------##
+
+include $(onf-mk-dir)/detect/include.mk     # Dynamic features based on source
+
 include $(onf-mk-dir)/lint/make/warn-undef-vars.mk  # target lint-make helper
 
 include $(onf-mk-dir)/consts.mk