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/igep00x0_defconfig b/configs/igep00x0_defconfig
index 04e9c95..ab0b3b7 100644
--- a/configs/igep00x0_defconfig
+++ b/configs/igep00x0_defconfig
@@ -43,6 +43,7 @@
 CONFIG_OF_CONTROL=y
 CONFIG_DEFAULT_DEVICE_TREE="omap3-igep0020"
 CONFIG_ENV_IS_IN_UBI=y
+CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
 CONFIG_ENV_UBI_PART="UBI"
 CONFIG_ENV_UBI_VOLUME="config"
 CONFIG_ENV_UBI_VOLUME_REDUND="config_r"