configs: Migrate and re-enabled CONFIG_CMD_MTDPARTS

Now that CMD_UBI does not select CMD_MTDPARTS we need to make platforms
that had been enabling it turn it on by hand.  This exposed that we had
not yet migrated CMD_MTDPARTS fully, so do so now.

Fixes: 86dfa556d927 ("cmd: ubi: Remove useless call to mtdparts_init()")
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/nas220_defconfig b/configs/nas220_defconfig
index 3c5c71f..6bd308b 100644
--- a/configs/nas220_defconfig
+++ b/configs/nas220_defconfig
@@ -21,6 +21,7 @@
 CONFIG_CMD_EXT4=y
 CONFIG_CMD_FAT=y
 CONFIG_CMD_JFFS2=y
+CONFIG_CMD_MTDPARTS=y
 CONFIG_CMD_UBI=y
 CONFIG_ISO_PARTITION=y
 CONFIG_EFI_PARTITION=y