Add CONFIG_HAS_ETH0 to all boards with TSEC

The 85xx code now relies on CONFIG_HAS_ETH0 to determine whether
to update TSEC1's device-tree node, so we need to add it
to all the boards with TSECs.  Do this for 83xx and 86xx, too,
since they will eventually do something similar.

Signed-off-by: Andy Fleming <afleming@freescale.com>
diff --git a/include/configs/MPC8541CDS.h b/include/configs/MPC8541CDS.h
index 33a153e..a4727b2 100644
--- a/include/configs/MPC8541CDS.h
+++ b/include/configs/MPC8541CDS.h
@@ -481,6 +481,7 @@
 
 /* The mac addresses for all ethernet interface */
 #if defined(CONFIG_TSEC_ENET)
+#define CONFIG_HAS_ETH0
 #define CONFIG_ETHADDR   00:E0:0C:00:00:FD
 #define CONFIG_HAS_ETH1
 #define CONFIG_ETH1ADDR  00:E0:0C:00:01:FD