wifi: mac80211_hwsim: use MLO link ID for TX

Use the link ID provided in TX frame metadata to select the correct
channel. For now, always select the link with the lowest link ID and
do some address translation.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>