hostapd: add IEEE 802.11k support

The sender domain has a DMARC Reject/Quarantine policy which disallows
sending mailing list messages using the original "From" header.

To mitigate this problem, the original message has been wrapped
automatically by the mailing list software.
Enables radio resource management to be reported by hostapd to clients.

Ref: https://github.com/lede-project/source/pull/1430
Co-developed-by: Lorenzo Santina <lorenzo.santina@edu.unito.it>
Signed-off-by: Lorenzo Santina <lorenzo.santina@edu.unito.it>
Signed-off-by: Kyle Copperfield <kmcopper@danwin1210.me>

package/network/services/hostapd/files/hostapd.sh

@@ -223,6 +223,8 @@ hostapd_common_add_bss_config() {
 	config_add_int time_advertisement
 	config_add_string time_zone
 
+	config_add_boolean ieee80211k rrm_neighbor_report rrm_beacon_report
+
 	config_add_boolean ieee80211r pmk_r1_push ft_psk_generate_local ft_over_ds
 	config_add_int r0_key_lifetime reassociation_deadline
 	config_add_string mobility_domain r1_key_holder
@@ -489,6 +491,17 @@ hostapd_set_bss_options() {
 		append bss_conf "bss_transition=$bss_transition" "$N"
 	fi
 
+	json_get_vars ieee80211k
+	set_default ieee80211k 0
+	if [ "$ieee80211k" -eq "1" ]; then
+		json_get_vars rrm_neighbor_report rrm_beacon_report
+
+		set_default rrm_neighbor_report 1
+		set_default rrm_beacon_report 1
+		append bss_conf "rrm_neighbor_report=$rrm_neighbor_report" "$N"
+		append bss_conf "rrm_beacon_report=$rrm_beacon_report" "$N"
+	fi
+
 	if [ "$wpa" -ge "1" ]; then
 		json_get_vars ieee80211r
 		set_default ieee80211r 0