USB core: fix recent kernel-doc warnings

Fix new kernel-doc warnings in usb core:

Warning(drivers/usb/core/usb.c:79): No description found for parameter 'config'
Warning(drivers/usb/core/usb.c:79): No description found for parameter 'iface_num'
Warning(drivers/usb/core/usb.c:79): No description found for parameter 'alt_num'
Warning(drivers/usb/core/hcd.c:1622): No description found for parameter 'udev'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>