wifi: iwlwifi: make debugfs entries link specific

All of the station elements are really elements for the link. Create
them from the correct callback and return the link specific information
rather than always using the default link.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230612184434.a8e0c40d325e.I374d9433c3b8694667e1ce550d65f6f1f0d23c05@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>