Blackfin: bf518f-ezbrd: increase monitor length

The addition of KGDB overflowed the current linker section.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

include/configs/bf518f-ezbrd.h

@@ -53,7 +53,7 @@
 #define CONFIG_EBIU_AMBCTL0_VAL	(B1WAT_15 | B1RAT_15 | B1HT_3 | B1RDYPOL | B0WAT_15 | B0RAT_15 | B0HT_3 | B0RDYPOL)
 #define CONFIG_EBIU_AMBCTL1_VAL	(B3WAT_15 | B3RAT_15 | B3HT_3 | B3RDYPOL | B2WAT_15 | B2RAT_15 | B2HT_3 | B2RDYPOL)
 
-#define CONFIG_SYS_MONITOR_LEN	(384 * 1024)
+#define CONFIG_SYS_MONITOR_LEN	(512 * 1024)
 #define CONFIG_SYS_MALLOC_LEN	(384 * 1024)