dm: sunxi: Use driver model for Ethernet on Linksprite pcDuino3

Switch this board over to use driver model for Ethernet.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/Linksprite_pcDuino3_defconfig b/configs/Linksprite_pcDuino3_defconfig
index 8c76a736..e5aabdb 100644
--- a/configs/Linksprite_pcDuino3_defconfig
+++ b/configs/Linksprite_pcDuino3_defconfig
@@ -17,3 +17,4 @@
 CONFIG_ETH_DESIGNWARE=y
 CONFIG_NETDEVICES=y
 CONFIG_NET=y
+CONFIG_DM_ETH=y