DFS: Add support for 80+80 MHz when going through channel switch

DFS: Add support for 80+80 MHz when going through channel switch

After a radar signal is detected, the AP should switch to another
channel, but in the case of 80+80 MHz, channel switch failed because
hostapd did not select the secondary channel in the process. Fix this by
selecting a secondary channel in the case of 80+80 MHz.

Signed-off-by: Xin Wang <xwangw@codeaurora.org>
Signed-off-by: Pravas Kumar Panda <kumarpan@codeaurora.org>