powerpc/mpc8536ds: Save the env variables to SDcard and SPI flash

MPC8536DS offer booting from SDcard or SPI flash.  This patch defined that
u-boot can save the environment variables on SDcard or SPI flash when
booting from the related device.  The Env parameter region and linux
kernel region have overlap in SPI-Flash, So change the Env param saving
address.
Signed-off-by: NXie Xiaobo <r63061@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

include/configs/MPC8536DS.h

@@ -644,10 +644,24 @@
 
 #if defined(CONFIG_SYS_RAMBOOT)
 #if defined(CONFIG_RAMBOOT_NAND)
-	#define CONFIG_ENV_IS_IN_NAND	1
-	#define CONFIG_ENV_SIZE		CONFIG_SYS_NAND_BLOCK_SIZE
-	#define CONFIG_ENV_OFFSET ((512 * 1024) + CONFIG_SYS_NAND_BLOCK_SIZE)
-#elif defined(CONFIG_RAMBOOT_SDCARD) || defined(CONFIG_RAMBOOT_SPIFLASH)
+#define CONFIG_ENV_IS_IN_NAND	1
+#define CONFIG_ENV_SIZE		CONFIG_SYS_NAND_BLOCK_SIZE
+#define CONFIG_ENV_OFFSET ((512 * 1024) + CONFIG_SYS_NAND_BLOCK_SIZE)
+#define CONFIG_ENV_RANGE	(3 * CONFIG_ENV_SIZE)
+#elif defined(CONFIG_RAMBOOT_SPIFLASH)
+#define CONFIG_ENV_IS_IN_SPI_FLASH
+#define CONFIG_ENV_SPI_BUS	0
+#define CONFIG_ENV_SPI_CS	0
+#define CONFIG_ENV_SPI_MAX_HZ	10000000
+#define CONFIG_ENV_SPI_MODE	0
+#define CONFIG_ENV_SIZE		0x2000	/* 8KB */
+#define CONFIG_ENV_OFFSET	0xF0000
+#define CONFIG_ENV_SECT_SIZE	0x10000
+#elif defined(CONFIG_RAMBOOT_SDCARD)
+#define CONFIG_ENV_IS_IN_MMC
+#define CONFIG_ENV_SIZE		0x2000
+#define CONFIG_SYS_MMC_ENV_DEV  0
+#else
 	#define CONFIG_ENV_IS_NOWHERE	1	/* Store ENV in memory only */
 	#define CONFIG_ENV_ADDR		(CONFIG_SYS_MONITOR_BASE - 0x1000)
 	#define CONFIG_ENV_SIZE		0x2000