new at91_emac network driver (NET_MULTI api)

* add's at91_emac (AT91RM9200) network driver (NET_MULTI api)
* enable driver with CONFIG_DRIVER_AT91EMAC
* generic PHY initialization
* modify AT91RM9200 boards to use NET_MULTI driver
* the drivers has been tested with LXT971 Phy and DM9161 Phy at
  MII and RMII interface

Signed-off-by: Jens Scharsig <js_at_ng@scharsoft.de>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index dc3107c..1ec0ba1 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -27,6 +27,7 @@
 
 COBJS-$(CONFIG_DRIVER_3C589) += 3c589.o
 COBJS-$(CONFIG_PPC4xx_EMAC) += 4xx_enet.o
+COBJS-$(CONFIG_DRIVER_AT91EMAC) += at91_emac.o
 COBJS-$(CONFIG_DRIVER_AX88180) += ax88180.o
 COBJS-$(CONFIG_BCM570x) += bcm570x.o bcm570x_autoneg.o 5701rls.o
 COBJS-$(CONFIG_BFIN_MAC) += bfin_mac.o