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>