wifi: iwlwifi: mvm: add support for the new LINK command

As a part of the new MLD FW API changes, we have a new LINK command
to add/remove/configure a link.
Add structures and enum definitions, along with the functions that
sends this command (i.e. add, remove and change mac ctxt).
These functions will be in used in the next patches.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230314194113.d7808329effb.I13bea2db206b78540bc866bc3ab755ad5be78c53@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>