defconfigs: Migrate CONFIG_SYS_REDUNDAND_ENVIRONMENT

Move this symbol to Kconfig.  As part of this we can drop a UBI-specific
symbol that was a stop-gap for not having this particular symbol in
Kconfig.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/pcm058_defconfig b/configs/pcm058_defconfig
index 879f993..3534d00 100644
--- a/configs/pcm058_defconfig
+++ b/configs/pcm058_defconfig
@@ -43,6 +43,7 @@
 CONFIG_CMD_UBI=y
 # CONFIG_SPL_PARTITION_UUIDS is not set
 CONFIG_ENV_IS_IN_SPI_FLASH=y
+CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
 CONFIG_DM=y
 CONFIG_FSL_USDHC=y
 CONFIG_MTD=y