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/tqma6s_mba6_spi_defconfig b/configs/tqma6s_mba6_spi_defconfig
index e02b8a5..85d4a22 100644
--- a/configs/tqma6s_mba6_spi_defconfig
+++ b/configs/tqma6s_mba6_spi_defconfig
@@ -33,6 +33,7 @@
 CONFIG_CMD_FAT=y
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_ENV_IS_IN_SPI_FLASH=y
+CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
 CONFIG_FSL_USDHC=y
 CONFIG_SPI_FLASH=y
 CONFIG_SF_DEFAULT_MODE=0