[][MAC80211][hostapd][Fix ZWDFS issue in BW 160]

[Description]
Fix ZWDFS issue in BW 160.
When background radar is enabled and bandwidth is set to 160, AP will
fail to startup due to the lack of non-DFS channel.
Under this circumstance, AP should perform CAC itself, and the background
chain could also perform CAC simultaneously.

[Release-log]
N/A

Change-Id: I49ddc9c288a7abc7374c5dde88bb90f8cba0f522
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7269167
1 file changed