wifi: rtw89: do RF calibration once setting channel when running pure monitor mode

wifi: rtw89: do RF calibration once setting channel when running pure monitor mode

To be able to capture and inject packets in monitor mode, do RF calibration
once setting certain channel. Since calibration costs time, do not change
behavior of normal usage, which do calibration only when starting as AP
or going to connect AP.

Since driver declares IEEE80211_HW_WANT_MONITOR_VIF, the pure monitor vif
must be only one when adding interface with type NL80211_IFTYPE_MONITOR.
Otherwise, monitor vif must be NULL.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20251111022452.28093-8-pkshih@realtek.com