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/omap5_uevm_defconfig b/configs/omap5_uevm_defconfig
index cd30110..036a367 100644
--- a/configs/omap5_uevm_defconfig
+++ b/configs/omap5_uevm_defconfig
@@ -25,6 +25,7 @@
 # CONFIG_CMD_SETEXPR is not set
 CONFIG_CMD_EXT4_WRITE=y
 CONFIG_ENV_IS_IN_MMC=y
+CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_SCSI_AHCI=y
 CONFIG_DFU_MMC=y