arm64: Enable dma_mmap_nonconsistent

Now that the non-consistent behavior is fully integrated into the
dma mapping subsystem, allow user space to mmap nonconsistent dma
buffers.

Change-Id: I1b95ba9a1751e00a5812d9df582af20f316fcafe
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>

Conflicts:
	arch/arm64/include/asm/dma-mapping.h

include/asm-generic/dma-mapping-common.h

@@ -348,7 +348,9 @@ static inline int dma_mmap_nonconsistent(struct device *dev,
 		struct vm_area_struct *vma, void *cpu_addr,
 		dma_addr_t dma_addr, size_t size)
 {
-	return -ENODEV;
+	DEFINE_DMA_ATTRS(attrs);
+	dma_set_attr(DMA_ATTR_NON_CONSISTENT, &attrs);
+	return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs);
 }
 
 #ifndef HAVE_ARCH_DMA_SUPPORTED