ARM: configs: at91: sama5: Enable LAN78XX as module

Include this driver as the USB-Ethernet chip is present on SAMA5D2-ICP
board.
Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>
[nicolas.ferre@microchip.com: update commit subject and message]
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>

arch/arm/configs/sama5_defconfig

@@ -89,6 +89,7 @@ CONFIG_MACB=y
 # CONFIG_NET_VENDOR_STMICRO is not set
 # CONFIG_NET_VENDOR_WIZNET is not set
 CONFIG_MICREL_PHY=y
+CONFIG_USB_LAN78XX=m
 CONFIG_LIBERTAS_THINFIRM=m
 CONFIG_LIBERTAS_THINFIRM_USB=m
 CONFIG_MWIFIEX=m