wifi: mac80211: restore monitor for outgoing frames

This code was accidentally dropped during the cooked
monitor removal, but really should've been simplified
instead. Add the simple version back.

Fixes: 286e6967 ("wifi: mac80211: Drop cooked monitor support")
Link: https://patch.msgid.link/20250422213251.b3d65fd0f323.Id2a6901583f7af86bbe94deb355968b238f350c6@changeid


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