mx25pdk: Use internal RAM for stack pointer

Use internal RAM for stack pointer as it is done in other i.MX boards.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/include/configs/mx25pdk.h b/include/configs/mx25pdk.h
index 96c143e..bd000a7 100644
--- a/include/configs/mx25pdk.h
+++ b/include/configs/mx25pdk.h
@@ -15,6 +15,8 @@
 #ifndef __CONFIG_H
 #define __CONFIG_H
 
+#include <asm/arch/imx-regs.h>
+
 /* High Level Configuration Options */
 
 #define CONFIG_SYS_HZ			1000
@@ -41,8 +43,13 @@
 #define CONFIG_BOARD_EARLY_INIT_F
 
 #define CONFIG_SYS_SDRAM_BASE		PHYS_SDRAM_1
-#define CONFIG_SYS_INIT_SP_ADDR		(CONFIG_SYS_SDRAM_BASE + 0x1000 - \
-						GENERATED_GBL_DATA_SIZE)
+#define CONFIG_SYS_INIT_RAM_ADDR	IMX_RAM_BASE
+#define CONFIG_SYS_INIT_RAM_SIZE	IMX_RAM_SIZE
+
+#define CONFIG_SYS_INIT_SP_OFFSET \
+	(CONFIG_SYS_INIT_RAM_SIZE - GENERATED_GBL_DATA_SIZE)
+#define CONFIG_SYS_INIT_SP_ADDR \
+	(CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_SP_OFFSET)
 
 /* Memory Test */
 #define CONFIG_SYS_MEMTEST_START	(PHYS_SDRAM_1 + PHYS_SDRAM_1_SIZE/2)