kconfig: add blank Kconfig files

This would be useful to start moving various config options.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/Kconfig b/lib/Kconfig
new file mode 100644
index 0000000..9724eb8
--- /dev/null
+++ b/lib/Kconfig
@@ -0,0 +1,3 @@
+menu "Library routines"
+
+endmenu