kconfig_lint: update kconfig lint shell scripts

- Add lint-stable script with just error checking
- Enable warnings in addition to errors in non-stable test.
- Use git grep if the code is in a git repo now that exclusions are
working.
- Check for perl, and ask the user to install it if it isn't
available.

Change-Id: Ie60d21f4ef8a61d879f116eb2056eb805b0a55f2
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/13542
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)

util/lint/lint-008-kconfig

@@ -12,7 +12,19 @@
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
-# DESCR: check Kconfig files
+# DESCR: check Kconfig files for warnings and errors
 
 LC_ALL=C export LC_ALL
-env perl util/lint/kconfig_lint --no_git_grep --warnings_off
+
+# Verify that the test can run, tell users the issue
+if [ -z "$(command -v perl)" ]; then
+	echo "The kconfig lint tool uses perl.  Please install it to run this test."
+fi
+
+# If coreboot is in a git repo, use git grep to check as it will ignore any
+# files in the tree that aren't checked into git
+if [ -n "$(command -v git)" ] && [ -e ".git" ]; then
+	env perl util/lint/kconfig_lint
+else
+	env perl util/lint/kconfig_lint --no_git_grep
+fi

util/lint/lint-stable-008-kconfig

@@ -0,0 +1,30 @@
+#!/bin/sh
+# This file is part of the coreboot project.
+#
+# Copyright 2016 Google Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# DESCR: check Kconfig files for errors
+
+LC_ALL=C export LC_ALL
+
+# Verify that the test can run, tell users the issue
+if [ -z "$(command -v perl)" ]; then
+	echo "The kconfig lint tool uses perl.  Please install it to run this test."
+fi
+
+# If coreboot is in a git repo, use git grep to check as it will ignore any
+# files in the tree that aren't checked into git
+if [ -n "$(command -v git)" ] && [ -e ".git" ]; then
+	env perl util/lint/kconfig_lint --warnings_off
+else
+	env perl util/lint/kconfig_lint --no_git_grep --warnings_off
+fi