kconfig: introduce kconfig for UBI

move the UBI config options into Kconfig.

Signed-off-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andrew F. Davis <afd@ti.com>
Reviewed by: Evgeni Dobrev <evgeni at studio-punkt.com>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index d28da54..9ed7976 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -705,4 +705,16 @@
 	  fs types.
 endmenu
 
+config CMD_UBI
+	tristate "Enable UBI - Unsorted block images commands"
+	select CRC32
+	select MTD_UBI
+	help
+	  UBI is a software layer above MTD layer which admits use of LVM-like
+	  logical volumes on top of MTD devices, hides some complexities of
+	  flash chips like wear and bad blocks and provides some other useful
+	  capabilities. Please, consult the MTD web site for more details
+	  (www.linux-mtd.infradead.org). Activate this option if you want
+	  to use U-Boot UBI commands.
+
 endmenu