Adder8xx: Fix CFG_MONITOR_LEN

Due to increased space usage, U-Boot can no longer be stored in three sectors.
The current U-Boot use just over three flash sectors (197k), and U-Boot will
become corrupt after saving environment variables. This patch adds another 64k
to CFG_MONITOR_LEN.
Signed-off-by: NFrank E. Svendsbøe <frank.svendsboe@gmail.com>

include/configs/Adder.h

@@ -131,7 +131,7 @@
 #define CFG_BOOTMAPSZ		(8 << 20)	/* Initial Memory map for Linux */
 
 #define CFG_MONITOR_BASE	TEXT_BASE
-#define CFG_MONITOR_LEN		(192 << 10)	/* Reserve 192 KB for Monitor   */
+#define CFG_MONITOR_LEN		(256 << 10)	/* Reserve 256 KB for Monitor   */
 #ifdef CONFIG_BZIP2
 #define CFG_MALLOC_LEN		(2500 << 10)	/* Reserve ~2.5 MB for malloc() */
 #else