env: Remove all dependencies for SYS_REDUNDAND_ENVIRONMENT

CONFIG_SYS_REDUNDAND_ENVIRONMENT is changing in env_internal.h how u-boot
works with variables. struct environment_s has one byte flags property
which also affects ENV_SIZE macro.

I have reached the case where CONFIG_ENV_IS_NOWHERE is default setup
but custom scripts can be designed in a way that u-boot is asked to
import/export variables from/to file which can be in certain format.
That's why also for this configuration make sense to enable
CONFIG_SYS_REDUNDAND_ENVIRONMENT because it depends on environment file
format.

The patch is removing dependency on this configuration to support selecting
environment file format without any specific dependency where variables are
stored.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

env/Kconfig

@@ -411,13 +411,14 @@ config ENV_IS_IN_UBI
 
 config SYS_REDUNDAND_ENVIRONMENT
 	bool "Enable redundant environment support"
-	depends on ENV_IS_IN_EEPROM || ENV_IS_IN_FLASH || ENV_IS_IN_MMC || \
-		ENV_IS_IN_NAND || ENV_IS_IN_SPI_FLASH || ENV_IS_IN_UBI
 	help
 	  Normally, the environemt is stored in a single location.  By
 	  selecting this option, you can then define where to hold a redundant
 	  copy of the environment data, so that there is a valid backup copy in
 	  case there is a power failure during a "saveenv" operation.
+	  Also this config changes the binary environment structure handling
+	  which is used by env import/export commands which are independent of
+	  storing variables to redundant location on a non volatile device.
 
 config ENV_FAT_INTERFACE
 	string "Name of the block device for the environment"