ARM: highbank: add coherent DMA setup

Some highbank DMA masters can support coherent (ACP) or non-coherent DMA.
This sets up dma_map_ops for masters which are configured for coherent DMA.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
diff --git a/arch/arm/boot/dts/highbank.dts b/arch/arm/boot/dts/highbank.dts
index 9fecf1a..7414577 100644
--- a/arch/arm/boot/dts/highbank.dts
+++ b/arch/arm/boot/dts/highbank.dts
@@ -121,6 +121,7 @@
 			compatible = "calxeda,hb-ahci";
 			reg = <0xffe08000 0x10000>;
 			interrupts = <0 83 4>;
+			dma-coherent;
 		};
 
 		sdhci@ffe0e000 {