mx28evk: Guard NAND-related ENV defines with CONFIG_ENV_IS_IN_NAND

The redundancy related defines are only correct for NAND, so guard all
of that area with CONFIG_ENV_IS_IN_NAND

Cc: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Tom Rini <trini@ti.com>

include/configs/mx28evk.h

@@ -138,14 +138,14 @@
 #define CONFIG_SYS_NAND_5_ADDR_CYCLE
 
 /* Environment is in NAND */
+#ifdef CONFIG_ENV_IS_IN_NAND
 #define CONFIG_ENV_SIZE_REDUND		CONFIG_ENV_SIZE
 #define CONFIG_ENV_SECT_SIZE		(128 * 1024)
 #define CONFIG_ENV_RANGE		(512 * 1024)
-#ifndef CONFIG_ENV_OFFSET
 #define CONFIG_ENV_OFFSET		0x300000
-#endif
 #define CONFIG_ENV_OFFSET_REDUND	\
 		(CONFIG_ENV_OFFSET + CONFIG_ENV_RANGE)
+#endif
 
 #define CONFIG_CMD_UBI
 #define CONFIG_CMD_UBIFS