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/configs/tuxx1_defconfig b/configs/tuxx1_defconfig
index f3f7857..02f98c9 100644
--- a/configs/tuxx1_defconfig
+++ b/configs/tuxx1_defconfig
@@ -15,5 +15,6 @@
 CONFIG_CMD_DHCP=y
 CONFIG_CMD_MII=y
 CONFIG_CMD_PING=y
+CONFIG_CMD_UBI=y
 CONFIG_SYS_NS16550=y
 CONFIG_OF_LIBFDT=y