rmu board: fix error: 'CONFIG_ENV_SECT_SIZE' undeclared

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/include/configs/rmu.h b/include/configs/rmu.h
index d88ae81..026826b 100644
--- a/include/configs/rmu.h
+++ b/include/configs/rmu.h
@@ -190,7 +190,8 @@
 
 #define	CONFIG_ENV_IS_IN_FLASH	1
 #define CONFIG_ENV_ADDR		((TEXT_BASE) + 0x40000)
-#define	CONFIG_ENV_SIZE		0x40000	/* Total Size of Environment Sector	*/
+#define	CONFIG_ENV_SECT_SIZE	0x40000		/* Total Size of Environment Sector	*/
+#define	CONFIG_ENV_SIZE		CONFIG_ENV_SECT_SIZE	/* Used size for environment	*/
 
 /* Address and size of Redundant Environment Sector	*/
 #define CONFIG_ENV_ADDR_REDUND	(CONFIG_ENV_ADDR+CONFIG_ENV_SIZE)