ath10k: introduce DFS implementation

Configure interface combination for AP running on channels
where radar detection is required. It allows only one type
of interface - AP on DFS channel and limits number of AP
interfaces to 8. Setup WMI channel flags accordingly to mac
channel configuration. CAC based on additional monitor vdev
is started if required for current channel.

kvalo: dropped ATH10K_DFS_CERTIFIED config option as this
the DFS still depends on few mac80211 and cfg80211 patches
which are on mac80211-next.git right now. The config option
will be added later once all dependencies are available.

Signed-off-by: Marek Puzyniak <marek.puzyniak@tieto.com>
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>