mpc8260: remove Ethernet node fixup to use generic FDT code.

Remove Ethernet node fixup from mgcoge and muas3001 boards and modify its
configs for the common mpc8260 code to use generic Ethernet fixup.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@noser.com>
Tested-by: Heiko Schocher <hs@denx.de>
diff --git a/include/configs/mgcoge.h b/include/configs/mgcoge.h
index ea14948..b955749 100644
--- a/include/configs/mgcoge.h
+++ b/include/configs/mgcoge.h
@@ -70,6 +70,7 @@
 #define CONFIG_NET_MULTI	1
 
 #define CONFIG_ETHER_INDEX	4
+#define CONFIG_HAS_ETH0
 #define CONFIG_SYS_SCC_TOUT_LOOP	10000000
 
 # define CONFIG_SYS_CMXSCR_VALUE	(CMXSCR_RS4CS_CLK7 | CMXSCR_TS4CS_CLK8)