qcacmn: Reset agile precac frequency during channel change

During abrupt channel change (e.g. iwconfig), the vap is brought
down and then brought back up. Now if the Agile detector is running
during this period, the detector is turned off as part of vap down.
When the vap comes back up, as part of starting the Agile detector,
a status of OCAC_SUCCESS and frequency of dfs->dfs_agile_precac_freq
is sent to the API (dfs_start_agile_precac_timer). The
dfs_agile_precac_freq variable was meant to be 0 as part of starting
the timer but since it was never cleared, that freq was moved to
Agile CAC done state immediately.

Clear the dfs_agile_precac_freq as part of vap down in addition to
stopping the Agile precac timer.

Change-Id: Ife117277a5d85911ae310e19a406f88fb9a544f0
CRs-Fixed: 2467077
1 file changed