When we associate, we'll include all the elements for the
link we're sending the association request on in the frame
and the specific ones for other links in the multi-link
element container. Prohibit adding link-specific elements
for the association link.

Fixes: d648c230 ("wifi: nl80211: support MLO in auth/assoc")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>