During channel switch, firmware reports CSA offload event,
driver will process wbw IE and set phy mode into firmware.
Now driver only processes case that frequency segment0 above
current primary channel. So device will use bandwidth which
is mismatched with AP after channel switch. It will cause data
transaction failure. Change to support frequency segment0 below
primary channel.
Change-Id: Ie879ceb8eadbe92f6519886dc30fb2c065ddbc40
CRs-Fixed: 2684883
7d713f4ae4