arm64: defconfig: enable stmmac ethernet to defconfig

This patch enables the CONFIG_STMMAC_ETH to the default arm64 defconfig:

-CONFIG_STMMAC_ETH=m
+CONFIG_STMMAC_ETH=y
+CONFIG_DWMAC_IPQ806X=m
+CONFIG_DWMAC_MESON=m
+CONFIG_DWMAC_ROCKCHIP=m
+CONFIG_DWMAC_SUNXI=m
+CONFIG_DWMAC_SUN8I=m

The STMMAC ethernet controller is on the Stratix10 platform, and thus needs
driver to be in the kernel image for NFS to work.
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

arch/arm64/configs/defconfig

@@ -209,7 +209,12 @@ CONFIG_QCOM_EMAC=m
 CONFIG_RAVB=y
 CONFIG_SMC91X=y
 CONFIG_SMSC911X=y
-CONFIG_STMMAC_ETH=m
+CONFIG_STMMAC_ETH=y
+CONFIG_DWMAC_IPQ806X=m
+CONFIG_DWMAC_MESON=m
+CONFIG_DWMAC_ROCKCHIP=m
+CONFIG_DWMAC_SUNXI=m
+CONFIG_DWMAC_SUN8I=m
 CONFIG_MDIO_BUS_MUX_MMIOREG=y
 CONFIG_AT803X_PHY=m
 CONFIG_MARVELL_PHY=m