[][kernel][mt7988][eth][Correct phy-mode for the USXGMII]

[Description]
Change DTS phy-mode to USXGMII instead of 10GKR except for SFP+.

According to the PHY specification, DE suggests chaning phy-mode
to USXGMII which connects with external 10G PHY.

[Release-log]
N/A


Change-Id: Ic51df5d1ee6ecf1ef572b28f3551a3450481e0ed
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7289672
diff --git a/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7988c-dsa-10g-spim-nor.dts b/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7988c-dsa-10g-spim-nor.dts
index 67c6508..3c06b94 100644
--- a/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7988c-dsa-10g-spim-nor.dts
+++ b/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7988c-dsa-10g-spim-nor.dts
@@ -192,7 +192,7 @@
 		phy-mode = "10gbase-kr";
 
 		fixed-link {
-			speed = <2500>;
+			speed = <10000>;
 			full-duplex;
 			pause;
 		};
@@ -202,7 +202,7 @@
 		compatible = "mediatek,eth-mac";
 		reg = <1>;
 		mac-type = "xgdm";
-		phy-mode = "10gbase-kr";
+		phy-mode = "usxgmii";
 		phy-handle = <&phy0>;
 	};