Blackfin: bf548-ezkit: bump up monitor size

The latest version of U-Boot got a bit fatter in the BSS section which
caused overflows in the RAM region, so increase the monitor size.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

include/configs/bf548-ezkit.h

@@ -61,7 +61,7 @@
 #define CONFIG_EBIU_FCTL_VAL	(BCLK_4)
 #define CONFIG_EBIU_MODE_VAL	(B0MODE_FLASH)
 
-#define CONFIG_SYS_MONITOR_LEN	(768 * 1024)
+#define CONFIG_SYS_MONITOR_LEN	(1024 * 1024)
 #define CONFIG_SYS_MALLOC_LEN	(768 * 1024)