wifi: mac80211: split mesh fast tx cache into local/proxied/forwarded

Depending on the origin of the packets (and their SA), 802.11 + mesh headers
could be filled in differently. In order to properly deal with that, add a
new field to the lookup key, indicating the type (local, proxied or
forwarded). This can fix spurious packet drop issues that depend on the order
in which nodes/hosts communicate with each other.

Fixes: d5edb9ae

 ("wifi: mac80211: mesh fast xmit support")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://msgid.link/20240415121811.13391-1-nbd@nbd.name
[use sizeof_field() for key_len]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>