High CAC timeout is seen for weather and non-weather DFS channels.
This is due to the delay in 5.4 Kernel timers. There is 1 second delay
observed for every 60 seconds.
To fix this issue, replace qdf timers with HR timer for CAC timeout.
On CAC expiry, when VDEV UP is sent to FW, serialization timer is
cancelled. Since CAC expiry is processed in H/W interrupt context
(while using HR timers), no other timer cancellation is allowed.
Hence, process the CAC timer completion in work queue context to allow
other timer cancellations by the CAC thread.
Change-Id: I92c4662decbba27261448327abb16708d941d778
CRs-Fixed: 3142394
8635ab3be9