mpc83xx: add missing CONFIG_HAS_ETH0 defines

the new libfdt code only updates eth0 if CONFIG_HAS_ETH0
is defined; add the define to the missing board configs.

Thanks to Emilian Medve for finding this.

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
diff --git a/include/configs/MPC8323ERDB.h b/include/configs/MPC8323ERDB.h
index 564de02..3521eb6 100644
--- a/include/configs/MPC8323ERDB.h
+++ b/include/configs/MPC8323ERDB.h
@@ -513,6 +513,7 @@
  */
 #define CONFIG_ENV_OVERWRITE
 
+#define CONFIG_HAS_ETH0				/* add support for "ethaddr" */
 #define CONFIG_ETHADDR	00:04:9f:ef:03:01
 #define CONFIG_HAS_ETH1				/* add support for "eth1addr" */
 #define CONFIG_ETH1ADDR	00:04:9f:ef:03:02