arm64: defconfig: enable the SerDes PHY for Qualcomm DWMAC

Enable the SGMII/SerDes PHY driver. This module is required to enable
ethernet on Qualcomm sa8775p platforms.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230622121141.218623-1-brgl@bgdev.pl
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Author: Bartosz Golaszewski

arch/arm64/configs/defconfig

@@ -1382,6 +1382,7 @@ CONFIG_PHY_QCOM_USB_HS=m
 CONFIG_PHY_QCOM_USB_SNPS_FEMTO_V2=m
 CONFIG_PHY_QCOM_USB_HS_28NM=m
 CONFIG_PHY_QCOM_USB_SS=m
+CONFIG_PHY_QCOM_SGMII_ETH=m
 CONFIG_PHY_R8A779F0_ETHERNET_SERDES=y
 CONFIG_PHY_RCAR_GEN3_PCIE=y
 CONFIG_PHY_RCAR_GEN3_USB2=y