mips: ath79: ap121: Enable ethernet

This patch enable network function for ap121 board.

Signed-off-by: Wills Wang <wills.wang@live.com>
Acked-by: Marek Vasut <marex@denx.de>
diff --git a/arch/mips/dts/ar933x.dtsi b/arch/mips/dts/ar933x.dtsi
index 00896b2..971f13e 100644
--- a/arch/mips/dts/ar933x.dtsi
+++ b/arch/mips/dts/ar933x.dtsi
@@ -75,7 +75,7 @@
 			};
 
 			gmac0: eth@0x19000000 {
-				compatible = "qca,ag7240-mac";
+				compatible = "qca,ag933x-mac";
 				reg = <0x19000000 0x200>;
 				phy = <&phy0>;
 				phy-mode = "rmii";
@@ -92,7 +92,7 @@
 			};
 
 			gmac1: eth@0x1a000000 {
-				compatible = "qca,ag7240-mac";
+				compatible = "qca,ag933x-mac";
 				reg = <0x1a000000 0x200>;
 				phy = <&phy0>;
 				phy-mode = "rgmii";