ARM: omap4_panda: enable saveenv command

Enable saveenv command and the configs to store environment
persistently in the SD card.

Tested on OMAP4 Panda (OMAP4460 ES1.1)
Signed-off-by: NMaxin B. John <maxin.john@enea.com>
Acked-by: NLokesh Vutla <lokeshvutla@ti.com>

include/configs/omap4_panda.h

@@ -43,8 +43,13 @@
 #define CONFIG_CMD_GPIO
 
 /* ENV related config options */
-#define CONFIG_ENV_IS_NOWHERE
 
 #define CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
+#define CONFIG_ENV_IS_IN_FAT
+#define FAT_ENV_INTERFACE               "mmc"
+#define FAT_ENV_DEVICE_AND_PART         "0:1"
+#define FAT_ENV_FILE                    "uboot.env"
+#define CONFIG_CMD_SAVEENV
+#define CONFIG_ENV_OVERWRITE
 
 #endif /* __CONFIG_PANDA_H */