arm64: Change misleading function names in dma-mapping

arm64_swiotlb_alloc/free_coherent name can be misleading
somtimes with CMA support being enabled after this
patch (c2104debc235b745265b64d610237a6833fd53)

Change this name to be more generic:
__dma_alloc/free_coherent
Signed-off-by: Ritesh Harjani <ritesh.harjani@gmail.com>
[catalin.marinas@arm.com: renamed arm64_swiotlb_dma_ops to coherent_swiotlb_dma_ops]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/mm/dma-mapping.c

@@ -30,7 +30,7 @@
 struct dma_map_ops *dma_ops;
 EXPORT_SYMBOL(dma_ops);
 
-static void *arm64_swiotlb_alloc_coherent(struct device *dev, size_t size,
+static void *__dma_alloc_coherent(struct device *dev, size_t size,
 				  dma_addr_t *dma_handle, gfp_t flags,
 				  struct dma_attrs *attrs)
 {
@@ -58,7 +58,7 @@ static void *arm64_swiotlb_alloc_coherent(struct device *dev, size_t size,
 	}
 }
 
-static void arm64_swiotlb_free_coherent(struct device *dev, size_t size,
+static void __dma_free_coherent(struct device *dev, size_t size,
 				void *vaddr, dma_addr_t dma_handle,
 				struct dma_attrs *attrs)
 {
@@ -78,9 +78,9 @@ static void arm64_swiotlb_free_coherent(struct device *dev, size_t size,
 	}
 }
 
-static struct dma_map_ops arm64_swiotlb_dma_ops = {
-	.alloc = arm64_swiotlb_alloc_coherent,
-	.free = arm64_swiotlb_free_coherent,
+static struct dma_map_ops coherent_swiotlb_dma_ops = {
+	.alloc = __dma_alloc_coherent,
+	.free = __dma_free_coherent,
 	.map_page = swiotlb_map_page,
 	.unmap_page = swiotlb_unmap_page,
 	.map_sg = swiotlb_map_sg_attrs,
@@ -95,7 +95,7 @@ static struct dma_map_ops arm64_swiotlb_dma_ops = {
 
 void __init arm64_swiotlb_init(void)
 {
-	dma_ops = &arm64_swiotlb_dma_ops;
+	dma_ops = &coherent_swiotlb_dma_ops;
 	swiotlb_init(1);
 }