dma-mapping: add a kconfig symbol for arch_setup_dma_ops availability

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Burton <paul.burton@mips.com> # MIPS
Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64

arch/mips/mm/dma-noncoherent.c

@@ -159,3 +159,11 @@ void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 
 	dma_sync_virt(vaddr, size, direction);
 }
+
+#ifdef CONFIG_DMA_PERDEV_COHERENT
+void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+		const struct iommu_ops *iommu, bool coherent)
+{
+	dev->dma_coherent = coherent;
+}
+#endif