An extension of preCAC feature is Rolling CAC. The distinct difference
between these features is that the FW runs the off channel CAC
timer for a "finite" time for preCAC and runs the timer for "infinite"
time on an off channel. Hence the infrastructure built for
preCAC feature is being modified to accommodate RCAC feature as well.
Following are the modifications done:
1. Add an enum to represent various off-channel CAC modes.
2. Remove the 'static' declaration of few APIS so as to re-use them.
3. Add 'dfs_rcac_ch_params' to DFS PDEV object to store the RCAC
channel params so as to use the channel params after radar detect.
4. Rename DFS APIs to match its functionality.
CRs-Fixed: 2670419
Change-Id: I0bf0d33955706941cffb4e9cf6fcebfb465a6c74