driver core: Add missing parameter description to __fwnode_link_add()

The kernel documentation validator is not happy with:

  drivers/base/core.c:67: warning: Function parameter or member 'flags' not described in '__fwnode_link_add'

Add missing parameter description.

Fixes: 6a6dfdf8 ("driver core: fw_devlink: Allow marking a fwnode link as being part of a cycle")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230919195048.3197551-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>