Makefile library merge with onf-make and voltha-lib-go

makefiles/
----------
  o Import standalone makefile directories to checkin smaller parts of a mega patch.
  o Build out directory hierarchy by topic and feature.

makefiles/lint/yaml/
--------------------
  o Pull in logic evolved in repo:voltha-lib-go.
  o Refactoring: support special snowflake targets by repository.
  o ci-management and voltha-lib-go use distinct yamllint.conf files.
  o Separate until there is time to review and consolidate.
  o Added deps for on-demand local install of yamllint.
    - requirements.txt could be used but every build would incur overhead.

Makefile
--------
  o Use latest syntax from repo:onf-make.
  o No need to set path variables, makefiles/include.mk can infer them.
  o Added a help target to explicitly display targets and suggestions.
  o Logic is bundled in libraries and use of 'make help' is not well known.

Change-Id: Id8eba6f914a7bfe9a31637901bd8fb78a387e0c2
diff --git a/makefiles/lint/yaml/install.mk b/makefiles/lint/yaml/install.mk
new file mode 100644
index 0000000..62b777d
--- /dev/null
+++ b/makefiles/lint/yaml/install.mk
@@ -0,0 +1,73 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
+#
+# Licensed under 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
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-FileCopyrightText: 2022 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-License-Identifier: Apache-2.0
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+## -----------------------------------------------------------------------
+## Intent: Install the yamllint tool
+## -----------------------------------------------------------------------
+.PHONY: lint-yaml-install
+
+# -----------------------------------------------------------------------
+# We can(/should?) define a command macro
+# wait a bit until use cases are better known.
+# Initial use required inserting xargs bash -c "$(YAMLLINT) {}"
+# -----------------------------------------------------------------------
+# YAMLLINT ?= $(venv-activate-bin)/yamllint
+# YAMLLINT ?= $(activate) && yamllint
+
+## -----------------------------------------------------------------------
+## Intent: Display yamllint command version string.
+##   Note: As a side effect, install yamllint by dependency
+## -----------------------------------------------------------------------
+.PHONY: lint-yaml-cmd-version
+lint-yaml-cmd-version : $(venv-activate-bin)/yamllint
+
+	$(HIDE) echo
+	$< --version
+
+## -----------------------------------------------------------------------
+## Intent: On-demand instalation of the yamllint command
+## -----------------------------------------------------------------------
+lint-yaml-install := $(venv-activate-bin)/yamllint
+$(lint-yaml-install) : $(venv-activate-script)
+
+	$(call banner-enter,Target $@)
+	$(activate) && pip install yamllint
+	$(call banner-leave,Target $@)
+
+## -----------------------------------------------------------------------
+## Intent: Purge yamllint tool installation
+## -----------------------------------------------------------------------
+sterile ::
+	$(HIDE)$(RM) "$(venv-abs-bin)/yamllint"
+	$(HIDE)$(RM) -r .venv/lib/*/site-packages/yamllint
+
+        # Remove both file:command and dir:libraries
+        # find "$(venv-abs-path)" -iname 'yamllint' -print0 \
+        #    | $(xargs-n1-clean) $(RM) -r {}
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
+help::
+	@echo '  lint-yaml-install       Install the yamllint tool'
+
+# [EOF]