wifi: iwlwifi: mvm: add an assign_vif_chanctx() callback for MLD mode

This is another patch in the series adding all the ops
for the new MLD ieee80211_ops.
The callback added here uses the new MLD FW API.

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.d3753975e720.I45f89cc81370d2cf8d4f51748ccb3ec675eff1bd@changeid


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