[][MAC80211][WiFi6][hostapd][core][Fix dead lock issue during post CSA radar detection]

[Description]
Fix dead lock issue during post CSA radar detection
1. Allow channel switch during post CSA radar detection.
2. Remove flush_delayed_work for DFS channel update work to avoid dead
lock. Instead, enqueue a DFS channel update work to reset the DFS state
of original channel from AVAILABLE to USABLE. This avoids AP jumping back to the original channel without performing CAC.
3. Add wait mechanism for immediate CSA finalize; otherwise channel
switch would fail due to the fact that other interfaces are not ready to switch.

[Release-log]
N/A

Change-Id: I19de89ae79bec235e55f0812895c6f875d487d87
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/8851056
2 files changed