ARM: dove: Remove UBI support from defconfig

As NAND support is not enabled by default, it's hard to see
why we'd want to have UBI support. Let's remove it.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

arch/arm/configs/dove_defconfig

@@ -48,7 +48,6 @@ CONFIG_MTD_CFI_INTELEXT=y
 CONFIG_MTD_CFI_STAA=y
 CONFIG_MTD_PHYSMAP=y
 CONFIG_MTD_M25P80=y
-CONFIG_MTD_UBI=y
 CONFIG_BLK_DEV_LOOP=y
 CONFIG_BLK_DEV_RAM=y
 CONFIG_BLK_DEV_RAM_COUNT=1