drm: Pass pointers to virt_to_page()

Most architectures define virt_to_page() as a macro that casts its
argument such that an argument of type unsigned long will be accepted
without complaint.  However, the proper type is void *, and passing
unsigned long results in a warning on MIPS.

Compile-tested only.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c
index f00d7a9..0267979 100644
--- a/drivers/gpu/drm/drm_pci.c
+++ b/drivers/gpu/drm/drm_pci.c
@@ -80,7 +80,7 @@
 	/* Reserve */
 	for (addr = (unsigned long)dmah->vaddr, sz = size;
 	     sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
-		SetPageReserved(virt_to_page(addr));
+		SetPageReserved(virt_to_page((void *)addr));
 	}
 
 	return dmah;
@@ -103,7 +103,7 @@
 		/* Unreserve */
 		for (addr = (unsigned long)dmah->vaddr, sz = dmah->size;
 		     sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
-			ClearPageReserved(virt_to_page(addr));
+			ClearPageReserved(virt_to_page((void *)addr));
 		}
 		dma_free_coherent(&dev->pdev->dev, dmah->size, dmah->vaddr,
 				  dmah->busaddr);