Currently the driver includes all the DFS channels as part of scan
in the scan list, and thus not exclude the DFS channels in the first
scan for faster scan.
Fix is to check the ini, for first DFS channel scan, and then remove
the DFS channels from the scan list if the ini is enabled.
Change-Id: Iff3361f3c1a577fd8e2b541a0673af431db65a5e
CRs-Fixed: 2378801