configs: sama5d2_xplained: enable CONFIG_DM_ETH

Enable CONFIG_DM_ETH to make MACB to support driver model.

Because the USB Ether doesn't support driver model so far,
remove this feature.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
diff --git a/configs/sama5d2_xplained_mmc_defconfig b/configs/sama5d2_xplained_mmc_defconfig
index 500f497..8378c4e 100644
--- a/configs/sama5d2_xplained_mmc_defconfig
+++ b/configs/sama5d2_xplained_mmc_defconfig
@@ -48,6 +48,8 @@
 CONFIG_DM_SPI_FLASH=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_ATMEL=y
+CONFIG_DM_ETH=y
+CONFIG_MACB=y
 CONFIG_PINCTRL=y
 CONFIG_PINCTRL_AT91PIO4=y
 CONFIG_DM_SERIAL=y