powerpc/mpc85xx:Update MONITOR_LEN for 768KB u-boot size

U-boot binary size has been increased from 512KB to 768KB.

So update CONFIG_SYS_MONITOR_LEN to reflect the same.

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/include/configs/P1023RDB.h b/include/configs/P1023RDB.h
index d7274f1..ba3da06 100644
--- a/include/configs/P1023RDB.h
+++ b/include/configs/P1023RDB.h
@@ -125,7 +125,7 @@
 					GENERATED_GBL_DATA_SIZE)
 #define CONFIG_SYS_INIT_SP_OFFSET	CONFIG_SYS_GBL_DATA_OFFSET
 
-#define CONFIG_SYS_MONITOR_LEN	(512 * 1024)	  /* Reserve 512 kB for Mon */
+#define CONFIG_SYS_MONITOR_LEN	(768 * 1024)	  /* Reserve 512 kB for Mon */
 #define CONFIG_SYS_MALLOC_LEN	(6 * 1024 * 1024) /* Reserved for malloc */
 
 #define CONFIG_SYS_NAND_BASE		0xffa00000