WiFi Drivers can advertize the number of bands dynamically. A check has been added to see if the band information is present and only then the values are extracted. Without this check, a kernel crash shall occur as we would extract the band information though the driver does not advertize. Change-Id: Ia726a692a3c2dcef2fcff0a59363053524c5f806 Signed-off-by: Sunil Dutt Undekari<duttus@codeaurora.org>