drm/radeon: use generic DMA API

Use generic DMA api instead of bus-specific API.
Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_device.c

@@ -784,9 +784,9 @@ int radeon_dummy_page_init(struct radeon_device *rdev)
 	rdev->dummy_page.page = alloc_page(GFP_DMA32 | GFP_KERNEL | __GFP_ZERO);
 	if (rdev->dummy_page.page == NULL)
 		return -ENOMEM;
-	rdev->dummy_page.addr = pci_map_page(rdev->pdev, rdev->dummy_page.page,
+	rdev->dummy_page.addr = dma_map_page(&rdev->pdev->dev, rdev->dummy_page.page,
 					0, PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
-	if (pci_dma_mapping_error(rdev->pdev, rdev->dummy_page.addr)) {
+	if (dma_mapping_error(&rdev->pdev->dev, rdev->dummy_page.addr)) {
 		dev_err(&rdev->pdev->dev, "Failed to DMA MAP the dummy page\n");
 		__free_page(rdev->dummy_page.page);
 		rdev->dummy_page.page = NULL;