AT91: Cleanup unused config header file definitions.

CONFIG_ENV_OVERWRITE is commented out in the config header files,
so let's cleanup the files by removing the whole definition.

Signed-off-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

include/configs/at91cap9adk.h

@@ -70,8 +70,6 @@
 
 #define CONFIG_BOOTDELAY	3
 
-/* #define CONFIG_ENV_OVERWRITE	1 */
-
 /*
  * BOOTP options
  */

include/configs/at91sam9260ek.h

@@ -57,8 +57,6 @@
 
 #define CONFIG_BOOTDELAY	3
 
-/* #define CONFIG_ENV_OVERWRITE	1 */
-
 /*
  * BOOTP options
  */

include/configs/at91sam9261ek.h

@@ -70,8 +70,6 @@
 
 #define CONFIG_BOOTDELAY	3
 
-/* #define CONFIG_ENV_OVERWRITE	1 */
-
 /*
  * BOOTP options
  */

include/configs/at91sam9263ek.h

@@ -70,8 +70,6 @@
 
 #define CONFIG_BOOTDELAY	3
 
-/* #define CONFIG_ENV_OVERWRITE	1 */
-
 /*
  * BOOTP options
  */

include/configs/at91sam9rlek.h

@@ -70,8 +70,6 @@
 
 #define CONFIG_BOOTDELAY	3
 
-/* #define CONFIG_ENV_OVERWRITE	1 */
-
 /*
  * Command line configuration.
  */