wifi: cfg80211: refactor RNR parsing

We'll need more parsing of the reduced neighbor report element,
and we already have two places doing pretty much the same.
Combine by refactoring the parsing into a separate function
with a callback for each item found.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240216135047.cfff14b692fc.Ibe25be88a769eab29ebb17b9d19af666df6a2227@changeid


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