wifi: cfg80211: use ML element parsing helpers

Use the existing ML element parsing helpers and add a new
one for this (ieee80211_mle_get_mld_id).

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240216135047.4da47b1f035b.I437a5570ac456449facb0b147851ef24a1e473c2@changeid


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