usb: chipidea: udc: fix the kernel doc for udc.h

The kernel doc for td_node is outdated, update it.
Signed-off-by: Peter Chen <peter.chen@nxp.com>

drivers/usb/chipidea/udc.h

@@ -67,10 +67,7 @@ struct td_node {
  * struct ci_hw_req - usb request representation
  * @req: request structure for gadget drivers
  * @queue: link to QH list
- * @ptr: transfer descriptor for this request
- * @dma: dma address for the transfer descriptor
- * @zptr: transfer descriptor for the zero packet
- * @zdma: dma address of the zero packet's transfer descriptor
+ * @tds: link to TD list
  */
 struct ci_hw_req {
 	struct usb_request	req;