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/ethernut5_defconfig b/configs/ethernut5_defconfig
index e7ebfef..1821b23 100644
--- a/configs/ethernut5_defconfig
+++ b/configs/ethernut5_defconfig
@@ -81,3 +81,4 @@
 CONFIG_SPI=y
 CONFIG_DM_SPI=y
 CONFIG_USB=y
+CONFIG_JFFS2_NAND=y