arm: dts: mediatek: Update mt7629 dts to reflect the latest dt-binding

* Removes mediatek,physpeed property from dtsi that is useless in PHYLINK
* Use the fixed-link property speed = <2500> to set the phy in 2.5Gbit.
* Set gmac1 to gmii mode that connect to a internal gphy

Signed-off-by: MarkLee <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

arch/arm/boot/dts/mt7629-rfb.dts

···
 	pinctrl-1 = <&ephy_leds_pins>;
 	status = "okay";
 
+	gmac0: mac@0 {
+		compatible = "mediatek,eth-mac";
+		reg = <0>;
+		phy-mode = "2500base-x";
+		fixed-link {
+			speed = <2500>;
+			full-duplex;
+			pause;
+		};
+	};
+
 	gmac1: mac@1 {
 		compatible = "mediatek,eth-mac";
 		reg = <1>;
+		phy-mode = "gmii";
 		phy-handle = <&phy0>;
 	};
 
···
 
 		phy0: ethernet-phy@0 {
 			reg = <0>;
-			phy-mode = "gmii";
 		};
 	};
 };

arch/arm/boot/dts/mt7629.dtsi

···
 			compatible = "mediatek,mt7629-sgmiisys", "syscon";
 			reg = <0x1b128000 0x3000>;
 			#clock-cells = <1>;
-			mediatek,physpeed = "2500";
 		};
 
 		sgmiisys1: syscon@1b130000 {
 			compatible = "mediatek,mt7629-sgmiisys", "syscon";
 			reg = <0x1b130000 0x3000>;
 			#clock-cells = <1>;
-			mediatek,physpeed = "2500";
 		};
 	};
 };