arm64: dts: mediatek: mt7622: add support for coherent DMA

It improves performance by eliminating the need for a cache flush on rx and tx
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/arm64/boot/dts/mediatek/mt7622.dtsi

@@ -357,7 +357,7 @@ cci_control1: slave-if@4000 {
 		};
 
 		cci_control2: slave-if@5000 {
-			compatible = "arm,cci-400-ctrl-if";
+			compatible = "arm,cci-400-ctrl-if", "syscon";
 			interface-type = "ace";
 			reg = <0x5000 0x1000>;
 		};
@@ -945,6 +945,8 @@ eth: ethernet@1b100000 {
 		power-domains = <&scpsys MT7622_POWER_DOMAIN_ETHSYS>;
 		mediatek,ethsys = <&ethsys>;
 		mediatek,sgmiisys = <&sgmiisys>;
+		mediatek,cci-control = <&cci_control2>;
+		dma-coherent;
 		#address-cells = <1>;
 		#size-cells = <0>;
 		status = "disabled";