[VOL-5297] - (dep for) Install pre-commit linting tool

.gitmodules
lf/onf-make
-----------
  o Add repo:onf-make (library makefiles) as a git submodule of the repo.
  o Submodule onf-make replaces legacy makefiles/ copy & paste logic
    with a common set of makefiles used across all voltha repositories.

lf/README.md
lf/include.mk
lf/local/include.mk
-------------------
  o Early config: install makefile loader(s) include.mk.

Change-Id: I4a8a94fc0fba64a7ab2a7192e935ba143e199cef
Signed-off-by: Joey Armstrong <jarmstrong@linuxfoundation.org>
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..0b23d6f
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "lf/onf-make"]
+	path = lf/onf-make
+	url = https://gerrit.opencord.org/onf-make