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/Kconfig b/Kconfig
index cbb691e..fc5e7cd 100644
--- a/Kconfig
+++ b/Kconfig
@@ -91,7 +91,7 @@
 	depends on !SPL_BUILD
 	help
 	  The old configuration infrastructure (= mkconfig + boards.cfg)
-	  provided the extra options field. It you have something like
+	  provided the extra options field. If you have something like
 	  "HAS_BAR,BAZ=64", the optional options
 	    #define CONFIG_HAS
 	    #define CONFIG_BAZ	64
@@ -103,3 +103,13 @@
 endmenu		# Boot images
 
 source "arch/Kconfig"
+
+source "common/Kconfig"
+
+source "net/Kconfig"
+
+source "drivers/Kconfig"
+
+source "fs/Kconfig"
+
+source "lib/Kconfig"