HID: usbhid: Implement may_wakeup ll-driver callback

Without a ll-driver callback hid_hw_may_wakeup() will return:
device_may_wakeup(hdev->dev.parent), usb_hid_driver instantiated hid
devices have their parent set to the usb-interface to which the
usb_hid_driver is bound, but the power/wakeup* sysfs attributes are
part of the usb-device.

Add a may_wakeup ll-driver callback which calls device_may_wakeup()
on the usb-device instead.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>