ARM: imx: imx8mn-ddr4-evk: Add ethernet support

Add support for ethernet on the imx8mn-ddr4-evk.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
diff --git a/configs/imx8mn_ddr4_evk_defconfig b/configs/imx8mn_ddr4_evk_defconfig
index 4f943a6..27bf5ec 100644
--- a/configs/imx8mn_ddr4_evk_defconfig
+++ b/configs/imx8mn_ddr4_evk_defconfig
@@ -65,7 +65,12 @@
 CONFIG_MMC_HS400_SUPPORT=y
 CONFIG_FSL_USDHC=y
 CONFIG_PHYLIB=y
+CONFIG_PHY_ATHEROS=y
 CONFIG_DM_ETH=y
+CONFIG_DM_ETH_PHY=y
+CONFIG_PHY_GIGE=y
+CONFIG_FEC_MXC=y
+CONFIG_MII=y
 CONFIG_PINCTRL=y
 CONFIG_SPL_PINCTRL=y
 CONFIG_PINCTRL_IMX8M=y