wifi: nl80211/cfg80211: support stations of non-netdev interfaces

wifi: nl80211/cfg80211: support stations of non-netdev interfaces

Currently, a station can only be added to a netdev interface,
mainly because there was no need for a station of a non-netdev
interface.

But for NAN, we will have stations that belong to the NL80211_IFTYPE_NAN
interface.

Prepare for adding/changing/deleting a station that belongs to a non-netdev
interface. This doesn't actually allow such stations - this will be done
in a different patch.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20260219114327.65c9cc96f814.Ic02066b88bb8ad6b21e15cbea8d720280008c83b@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>