wifi: mac80211: reject per-band vendor elements with MLO

The MLME code doesn't currently handle adding vendor elements
correctly with multi-link due to element inheritance. Simply
prevent that for now completely, if someone needs it we can
fix this later.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250101070249.bb82d3aaf6ef.Ib30573d0666430a3d7a905e513dfc661edf0bf65@changeid


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