udoo_neo: Fix ethernet

The ethernet has a RMII not RGMII, also needs DM_MDIO and finally
initialise it later in the process as it's not needed that early on
and not everything is ready so it locks up the device.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/configs/udoo_neo_defconfig b/configs/udoo_neo_defconfig
index f01d2e2..2a37757 100644
--- a/configs/udoo_neo_defconfig
+++ b/configs/udoo_neo_defconfig
@@ -46,8 +46,8 @@
 CONFIG_PHY_MICREL=y
 CONFIG_PHY_MICREL_KSZ8XXX=y
 CONFIG_DM_ETH=y
+CONFIG_DM_MDIO=y
 CONFIG_FEC_MXC=y
-CONFIG_RGMII=y
 CONFIG_MII=y
 CONFIG_PINCTRL=y
 CONFIG_PINCTRL_IMX6=y