wifi: cfg80211: reject bad AP MLD address

When trying to authenticate, if the AP MLD address isn't
a valid address, mac80211 can throw a warning. Avoid that
by rejecting such addresses.

Fixes: d648c230

 ("wifi: nl80211: support MLO in auth/assoc")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230604120651.89188912bd1d.I8dbc6c8ee0cb766138803eec59508ef4ce477709@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>