env: Add support for UBI environment

UBI is a better place for the environment on NAND devices because it
handles wear-leveling and bad blocks.

Gluebi is needed in Linux to access the env as an MTD partition.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c
index fab8694..afa128e 100644
--- a/common/cmd_nvedit.c
+++ b/common/cmd_nvedit.c
@@ -62,9 +62,10 @@
 	!defined(CONFIG_ENV_IS_IN_ONENAND)	&& \
 	!defined(CONFIG_ENV_IS_IN_SPI_FLASH)	&& \
 	!defined(CONFIG_ENV_IS_IN_REMOTE)	&& \
+	!defined(CONFIG_ENV_IS_IN_UBI)		&& \
 	!defined(CONFIG_ENV_IS_NOWHERE)
 # error Define one of CONFIG_ENV_IS_IN_{EEPROM|FLASH|DATAFLASH|ONENAND|\
-SPI_FLASH|NVRAM|MMC|FAT|REMOTE} or CONFIG_ENV_IS_NOWHERE
+SPI_FLASH|NVRAM|MMC|FAT|REMOTE|UBI} or CONFIG_ENV_IS_NOWHERE
 #endif
 
 /*