Convert CONFIG_JFFS2_DEV et al to Kconfig

This converts the following to Kconfig:
   CONFIG_JFFS2_DEV
   CONFIG_JFFS2_LZO
   CONFIG_JFFS2_NAND
   CONFIG_JFFS2_PART_OFFSET
   CONFIG_JFFS2_PART_SIZE

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/nas220_defconfig b/configs/nas220_defconfig
index 259eb2f..7e4e19a 100644
--- a/configs/nas220_defconfig
+++ b/configs/nas220_defconfig
@@ -54,3 +54,5 @@
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_STORAGE=y
+CONFIG_JFFS2_LZO=y
+CONFIG_JFFS2_NAND=y