ARM: highbank: enable coherent DMA for xgmac in dts

Enable the xgmac to use the coherent DMA path in highbank.dts

Signed-off-by: Rob Herring <[e-mail]>
Acked-by: Arnd Bergmann <[e-mail]>

arch/arm/boot/dts/highbank.dts

···
 			compatible = "calxeda,hb-xgmac";
 			reg = <0xfff50000 0x1000>;
 			interrupts = <0 77 4  0 78 4  0 79 4>;
+			dma-coherent;
 		};
 
 		ethernet@fff51000 {
 			compatible = "calxeda,hb-xgmac";
 			reg = <0xfff51000 0x1000>;
 			interrupts = <0 80 4  0 81 4  0 82 4>;
+			dma-coherent;
 		};
 
 		combophy0: combo-phy@fff58000 {