Remove redundant #define for MPC8536DS

Signed-off-by: Haiying Wang <Haiying.Wang@freescale.com>
diff --git a/include/configs/MPC8536DS.h b/include/configs/MPC8536DS.h
index 0d65b20..b504add 100644
--- a/include/configs/MPC8536DS.h
+++ b/include/configs/MPC8536DS.h
@@ -303,7 +303,6 @@
  */
 #define CONFIG_ID_EEPROM
 #ifdef CONFIG_ID_EEPROM
-#define CONFIG_ID_EEPROM
 #define CFG_I2C_EEPROM_NXID
 #endif
 #define CFG_I2C_EEPROM_ADDR	0x57