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/P1022DS.h b/include/configs/P1022DS.h
index 139d4fe..959cdf6 100644
--- a/include/configs/P1022DS.h
+++ b/include/configs/P1022DS.h
@@ -352,7 +352,7 @@
 	(CONFIG_SYS_INIT_RAM_SIZE - GENERATED_GBL_DATA_SIZE)
 #define CONFIG_SYS_INIT_SP_OFFSET	CONFIG_SYS_GBL_DATA_OFFSET
 
-#define CONFIG_SYS_MONITOR_LEN		(512 * 1024)
+#define CONFIG_SYS_MONITOR_LEN		(768 * 1024)
 #define CONFIG_SYS_MALLOC_LEN		(10 * 1024 * 1024)
 
 /*