colibri_imx6: migrate to DM_ETH

Migrate to DM_ETH and remove hardcoded pinmux configuration.

Signed-off-by: Igor Opaniuk <igor.opaniuk@toradex.com>
Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
diff --git a/configs/colibri_imx6_defconfig b/configs/colibri_imx6_defconfig
index bc5d5bf..8535aae 100644
--- a/configs/colibri_imx6_defconfig
+++ b/configs/colibri_imx6_defconfig
@@ -65,6 +65,9 @@
 CONFIG_PHYLIB=y
 CONFIG_PHY_MICREL=y
 CONFIG_PHY_MICREL_KSZ8XXX=y
+CONFIG_DM_ETH=y
+CONFIG_DM_MDIO=y
+CONFIG_FEC_MXC=y
 CONFIG_MII=y
 CONFIG_PINCTRL=y
 CONFIG_PINCTRL_IMX6=y