mpc85xx/T1040QDS_D4: Add DDR4 support

T1040QDS_D4 is a variant of T1040QDS, with additional circuit to support
DDR4 memory. Tested with MTA9ASF51272AZ-2G1AYESZG.

Signed-off-by: York Sun <yorksun@freescale.com>
diff --git a/include/configs/T1040QDS.h b/include/configs/T1040QDS.h
index 84213b8..63a7efc 100644
--- a/include/configs/T1040QDS.h
+++ b/include/configs/T1040QDS.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 Freescale Semiconductor, Inc.
+ * Copyright 2013-2014 Freescale Semiconductor, Inc.
  *
  * See file CREDITS for list of people who contributed to this
  * project.
@@ -169,8 +169,10 @@
 #define CONFIG_CHIP_SELECTS_PER_CTRL	(2 * CONFIG_DIMM_SLOTS_PER_CTLR)
 
 #define CONFIG_DDR_SPD
+#ifndef CONFIG_SYS_FSL_DDR4
 #define CONFIG_SYS_FSL_DDR3
 #define CONFIG_FSL_DDR_INTERACTIVE
+#endif
 
 #define CONFIG_SYS_SPD_BUS_NUM	0
 #define SPD_EEPROM_ADDRESS	0x51