imx: aristainetos: enable U-Boot Environment variables protection

enable Environment protection with:

CONFIG_ENV_APPEND=y
CONFIG_ENV_WRITEABLE_LIST=y
CONFIG_ENV_ACCESS_IGNORE_FORCE

and add board specific env_get_location()
function.

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/include/configs/aristainetos2.h b/include/configs/aristainetos2.h
index c1e8b4a..78fa1a9 100644
--- a/include/configs/aristainetos2.h
+++ b/include/configs/aristainetos2.h
@@ -449,4 +449,7 @@
 
 #define CONFIG_IMX6_PWM_PER_CLK	66000000
 
+#define CONFIG_ENV_FLAGS_LIST_STATIC "ethaddr:mw,serial#:sw,board_type:sw," \
+		"sysnum:dw,panel:sw,ipaddr:iw,serverip:iw"
+
 #endif                         /* __ARISTAINETOS2_CONFIG_H */