bitbake: Add missing documentation Makefile

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/doc/Makefile

@@ -0,0 +1,35 @@
+# Minimal makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line, and also
+# from the environment for the first two.
+SPHINXOPTS    ?=
+SPHINXBUILD   ?= sphinx-build
+SOURCEDIR     = .
+BUILDDIR      = _build
+DESTDIR       = final
+
+ifeq ($(shell if which $(SPHINXBUILD) >/dev/null 2>&1; then echo 1; else echo 0; fi),0)
+$(error "The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed")
+endif
+
+# Put it first so that "make" without argument is like "make help".
+help:
+	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+
+.PHONY: help Makefile clean publish
+
+publish: Makefile html singlehtml
+	rm -rf $(BUILDDIR)/$(DESTDIR)/
+	mkdir -p $(BUILDDIR)/$(DESTDIR)/
+	cp -r $(BUILDDIR)/html/* $(BUILDDIR)/$(DESTDIR)/
+	cp $(BUILDDIR)/singlehtml/index.html $(BUILDDIR)/$(DESTDIR)/singleindex.html
+	sed -i -e 's@index.html#@singleindex.html#@g' $(BUILDDIR)/$(DESTDIR)/singleindex.html
+
+clean:
+	@rm -rf $(BUILDDIR)
+
+# Catch-all target: route all unknown targets to Sphinx using the new
+# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
+%: Makefile
+	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)