pxa: balloon3/colibri_pxa270: fix environment optionally being nowhere

I couldn't quite figure out whether or not CONFIG_SYS_ENV_IS_NOWHERE
actually ever worked but nowadays this is called CONFIG_ENV_IS_NOWHERE.

Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>
diff --git a/include/configs/balloon3.h b/include/configs/balloon3.h
index e7f0345..848a158 100644
--- a/include/configs/balloon3.h
+++ b/include/configs/balloon3.h
@@ -134,7 +134,7 @@
 #define	CONFIG_ENV_IS_IN_FLASH
 #else
 #define	CONFIG_SYS_NO_FLASH
-#define	CONFIG_SYS_ENV_IS_NOWHERE
+#define	CONFIG_ENV_IS_NOWHERE
 #endif
 
 #define	CONFIG_SYS_MONITOR_BASE		0x000000