ppc4xx: Fix APC405 board support

Opps, after a long time I tested recent u-boot on our
APC405 board. This simple fix makes networking work again.
Signed-off-by: NMatthias Fuchs <matthias.fuchs@esd.eu>
Signed-off-by: NStefan Roese <sr@denx.de>

include/configs/APC405.h

@@ -104,6 +104,7 @@
 #define CONFIG_NET_MULTI	1
 #undef  CONFIG_HAS_ETH1
 
+#define CONFIG_PPC4xx_EMAC
 #define CONFIG_MII		1	/* MII PHY management		*/
 #define CONFIG_PHY_ADDR		0	/* PHY address			*/
 #define CONFIG_LXT971_NO_SLEEP	1