[RFC 3/3] stk1160: Use non-coherent buffers for USB transfers

+	dma_sync_single_for_cpu(&urb->dev->dev, urb->transfer_dma,
+		urb->transfer_buffer_length, DMA_FROM_DEVICE);

You can't ue dma_sync_single_for_cpu on non-coherent dma buffers,
which is one of the major issues with them.