arm: atmel: cpux9k2: increase malloc space to fix crash on start u-boot

Since UBIFS is enabled for cpux9k2, more malloc space is needed.
For the current uboot 2013.10-rcX the size is to small, this will fix the
startup problems by increasing the malloc space to 4MiB.
Signed-off-by: NJens Scharsig (BuS Elektronik) <esw@bus-elektronik.de>
Signed-off-by: NAndreas Bießmann <andreas.devel@googlemail.com>

include/configs/eb_cpux9k2.h

@@ -83,7 +83,7 @@
  * Size of malloc() pool
  */
 
-#define CONFIG_SYS_MALLOC_LEN		(CONFIG_ENV_SIZE + 520*1024)
+#define CONFIG_SYS_MALLOC_LEN		(4 * 1024 * 1024)
 
 /*
  * sdram