x86: Convert minnowmax to use CONFIG_DM_NET

Move to driver model for networking on minnowmax.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/configs/minnowmax_defconfig b/configs/minnowmax_defconfig
index 2d9fa8c..578fcce 100644
--- a/configs/minnowmax_defconfig
+++ b/configs/minnowmax_defconfig
@@ -18,6 +18,7 @@
 CONFIG_CPU=y
 CONFIG_DM_PCI=y
 CONFIG_SPI_FLASH=y
+CONFIG_DM_ETH=y
 CONFIG_DEBUG_UART=y
 CONFIG_DEBUG_UART_BASE=0x3f8
 CONFIG_DEBUG_UART_CLOCK=1843200