airoha: Add Ethernet config to defconfig

Add Ethrnet config to defconfig to enable Ethernet support.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
diff --git a/configs/an7581_evb_defconfig b/configs/an7581_evb_defconfig
index f09b5b6..f5bd647 100644
--- a/configs/an7581_evb_defconfig
+++ b/configs/an7581_evb_defconfig
@@ -76,3 +76,4 @@
 CONFIG_SPI=y
 CONFIG_DM_SPI=y
 CONFIG_SHA512=y
+CONFIG_AIROHA_ETH=y