powerpc/85xx: Enable ECC on MPC8572DS

Using hwconfig to turn on/off ECC, without re-compiling.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

include/configs/MPC8572DS.h

@@ -136,6 +136,7 @@
 #define CONFIG_SPD_EEPROM		/* Use SPD EEPROM for DDR setup */
 #define CONFIG_DDR_SPD
 
+#define CONFIG_DDR_ECC
 #define CONFIG_ECC_INIT_VIA_DDRCONTROLLER
 #define CONFIG_MEM_INIT_VALUE	0xDeadBeef