support USB 3.2 function remote wake

[Chunfeng Yun]

Hi,

I plan to support function remote wakeup on our usb3 device controller
driver.

A function may signal that it wants to exit from Function Suspend by
sending a Function Wake Notification to the host, and the notification
need knows the first interface number in this function.
But the current gadget ops:
    int (*wakeup)(struct usb_gadget *);
does not provide information about interface number;

There seems to be two ways:
1. add a new parameter as below,
    int (*wakeup)(struct usb_gadget *, u8 intf);
2. add a new ops, such as,
    int (*function_wakeup)(struct usb_gadget *, u8 intf);

Do you have any suggestions?

Thanks a lot