fotg210-udc: pass struct device to DMA API functions

The DMA API generally relies on a struct device to work properly, and
only barely works without one for legacy reasons.  Pass the easily
available struct device from the platform_device to remedy this.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/udc/fotg210-udc.c

@@ -326,6 +326,7 @@ static void fotg210_wait_dma_done(struct fotg210_ep *ep)
 static void fotg210_start_dma(struct fotg210_ep *ep,
 			struct fotg210_request *req)
 {
+	struct device *dev = &ep->fotg210->gadget.dev;
 	dma_addr_t d;
 	u8 *buffer;
 	u32 length;
@@ -348,10 +349,10 @@ static void fotg210_start_dma(struct fotg210_ep *ep,
 			length = req->req.length;
 	}
 
-	d = dma_map_single(NULL, buffer, length,
+	d = dma_map_single(dev, buffer, length,
 			ep->dir_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
 
-	if (dma_mapping_error(NULL, d)) {
+	if (dma_mapping_error(dev, d)) {
 		pr_err("dma_mapping_error\n");
 		return;
 	}
@@ -366,7 +367,7 @@ static void fotg210_start_dma(struct fotg210_ep *ep,
 	/* update actual transfer length */
 	req->req.actual += length;
 
-	dma_unmap_single(NULL, d, length, DMA_TO_DEVICE);
+	dma_unmap_single(dev, d, length, DMA_TO_DEVICE);
 }
 
 static void fotg210_ep0_queue(struct fotg210_ep *ep,