ubi: Kconfig: Make MTD_UBI select MTD_PARTITIONS

This missing dependency has probably remained under the radar because
MTD_PARTITIONS is still whitelisted.

Signed-off-by: Karl Beldan <karl.beldan-ext@sagemcom.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

drivers/mtd/ubi/Kconfig

@@ -4,6 +4,7 @@ config MTD_UBI
 	bool "Enable UBI - Unsorted block images"
 	select CRC32
 	select RBTREE
+	select MTD_PARTITIONS
 	help
 	  UBI is a software layer above MTD layer which admits of LVM-like
 	  logical volumes on top of MTD devices, hides some complexities of