[][MAC80211][core][Mark DFS channel available for CSA]

[Description]
Add optional parameter to mark DFS channel as available for CSA.
WFA TGac VHT-4.2.16h-DFS requires CSA while switching to DFS channel.
Hostapd original behavior is to disable/enable interface to move to new
channel.
"skip_cac" parameter is optional in command hostapd_cli chan_switch.
When not used, original hostapd behavior is followed for channel switch.

Use NL80211_ATTR_RADAR_BACKGROUND attribute for skipping CAC.

[Release-log]

Change-Id: I24ef8aa8f129bcc62a5ac4898cac331e93d60d4c
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7162083
1 file changed