[][kernel][mt7988][eth][Change AQR113C firmware download method to MDIO gangload]

[Description]
Change AQR113C firmware download method to MDIO gangload.

If without this patch, AQR113C cannot boot from MDIO gangload.

[Release-log]
N/A


Change-Id: Iddc29f5e1c73c772bcea9313938b6daccc10025a
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6781059
diff --git a/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7988a-dsa-10g-spim-nor.dts b/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7988a-dsa-10g-spim-nor.dts
index 35982e3..cdc692c 100644
--- a/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7988a-dsa-10g-spim-nor.dts
+++ b/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7988a-dsa-10g-spim-nor.dts
@@ -117,6 +117,18 @@
 };
 
 &pio {
+	mdio0_pins: mdio0-pins {
+		mux {
+			function = "mdio";
+			groups = "mdc_mdio0";
+		};
+
+		conf {
+			groups = "mdc_mdio0";
+			drive-strength = <MTK_DRIVE_8mA>;
+		};
+	};
+
 	pcie0_pins: pcie0-pins {
 		mux {
 			function = "pcie";
@@ -169,6 +181,8 @@
 };
 
 &eth {
+	pinctrl-names = "default";
+	pinctrl-0 = <&mdio0_pins>;
 	status = "okay";
 
 	gmac0: mac@0 {
@@ -203,6 +217,8 @@
 	mdio: mdio-bus {
 		#address-cells = <1>;
 		#size-cells = <0>;
+		mdc-max-frequency = <10500000>;
+
 		phy0: ethernet-phy@0 {
 			reg = <0>;
 			compatible = "ethernet-phy-ieee802.3-c45";