env: Migrate CONFIG_ENV_AES to Kconfig and deprecate

The underlying implementation for ENV_AES has security complications and
is not recommended for use.  Please see CVE-2017-3225 and CVE-2017-3226
for more details.  Mark this as deprecated now and delete this in the
medium term if no one comes forward to re-work the support.

Signed-off-by: Tom Rini <trini@konsulko.com>

env/Kconfig

@@ -375,6 +375,14 @@ config ENV_IS_IN_UBI
 
 endchoice
 
+config ENV_AES
+	bool "AES-128 encryption for stored environment (DEPRECATED)"
+	help
+	  Enable this to have the on-device stored environment be encrypted
+	  with AES-128.  The implementation here however has security
+	  complications and is not recommended for use.  Please see
+	  CVE-2017-3225 and CVE-2017-3226 for more details.
+
 config ENV_FAT_INTERFACE
 	string "Name of the block device for the environment"
 	depends on ENV_IS_IN_FAT

scripts/config_whitelist.txt

@@ -574,7 +574,6 @@ CONFIG_ENV_ACCESS_IGNORE_FORCE
 CONFIG_ENV_ADDR
 CONFIG_ENV_ADDR_FLEX
 CONFIG_ENV_ADDR_REDUND
-CONFIG_ENV_AES
 CONFIG_ENV_BASE
 CONFIG_ENV_CALLBACK_LIST_DEFAULT
 CONFIG_ENV_CALLBACK_LIST_STATIC