ramips: mt7621-dts: change phy-mode of gmac1 to rgmii

Change phy-mode of gmac1 to rgmii on mt7621.dtsi. Same code path is
followed for delayed rgmii and rgmii phy-mode on mtk_eth_soc.c.

Signed-off-by: Arınç ÜNAL <[email protected]>

target/linux/ramips/dts/mt7621.dtsi

@@ -505,7 +505,7 @@
 			compatible = "mediatek,eth-mac";
 			reg = <1>;
 			status = "disabled";
-			phy-mode = "rgmii-rxid";
+			phy-mode = "rgmii";
 		};
 
 		mdio: mdio-bus {