usb/max3421: remove the dummy {un,}map_urb_for_dma methods

Now that we have an explicit HCD_DMA flag, there is not need to override
these methods.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20190816062435.881-5-hch@lst.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/max3421-hcd.c

@@ -1800,21 +1800,6 @@ max3421_bus_resume(struct usb_hcd *hcd)
 	return -1;
 }
 
-/*
- * The SPI driver already takes care of DMA-mapping/unmapping, so no
- * reason to do it twice.
- */
-static int
-max3421_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
-{
-	return 0;
-}
-
-static void
-max3421_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
-{
-}
-
 static const struct hc_driver max3421_hcd_desc = {
 	.description =		"max3421",
 	.product_desc =		DRIVER_DESC,
@@ -1826,8 +1811,6 @@ static const struct hc_driver max3421_hcd_desc = {
 	.get_frame_number =	max3421_get_frame_number,
 	.urb_enqueue =		max3421_urb_enqueue,
 	.urb_dequeue =		max3421_urb_dequeue,
-	.map_urb_for_dma =	max3421_map_urb_for_dma,
-	.unmap_urb_for_dma =	max3421_unmap_urb_for_dma,
 	.endpoint_disable =	max3421_endpoint_disable,
 	.hub_status_data =	max3421_hub_status_data,
 	.hub_control =		max3421_hub_control,