wifi: iwlwifi: mvm: implement link change ops

Implement the link change ops for links and stations.
Note that the stations one is empty for now as we only
have support for a single link so far, and then the
stations are created with the first link as deflink by
mac80211, so right now we don't really need anything.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230328104949.6186c5a37e99.Ifd00d3ee93356ddef273aa18f1e081cd8f2c84ae@changeid


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