local-node: prioritize neighbor candidates

Prioritize neighbor candidates installed to hostapd. Add a new config
option to set a limit for neighbor reports installed to hostapd. This is
due to the fact, most devices will only evaluate a certain amount of
neighbor reports. Furthermore, the number of neighbor reports possible
is limited by the maximum frame size.

Signed-off-by: David Bauer <mail@david-bauer.net>

ubus.c

@@ -146,6 +146,7 @@ struct cfg_item {
 	_cfg(U32, sta_block_timeout), \
 	_cfg(U32, local_sta_timeout), \
 	_cfg(U32, local_sta_update), \
+	_cfg(U32, max_neighbor_reports), \
 	_cfg(U32, max_retry_band), \
 	_cfg(U32, seen_policy_timeout), \
 	_cfg(U32, load_balancing_threshold), \