drm/qxl: change the way slot is detected

Instead of relaying on surface type use the actual placement.
This allow to have different placement for a single type of
surface.
Signed-off-by: NFrediano Ziglio <fziglio@redhat.com>
Acked-by: NNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20190118122020.27596-5-kraxel@redhat.com

[ kraxel: rebased, adapted to upstream changes ]
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/qxl/qxl_drv.h

@@ -311,7 +311,8 @@ static inline uint64_t
 qxl_bo_physical_address(struct qxl_device *qdev, struct qxl_bo *bo,
 			unsigned long offset)
 {
-	struct qxl_memslot *slot = bo->type == QXL_GEM_DOMAIN_VRAM
+	struct qxl_memslot *slot =
+		(bo->tbo.mem.mem_type == TTM_PL_VRAM)
 		? &qdev->main_slot : &qdev->surfaces_slot;
 
 	/* TODO - need to hold one of the locks to read tbo.offset */