When wide band scan is enabled, host configures all possible
channels with all possible phy modes. In his case if a scan
is invoked with 0 channels, target will end up scanning each
channel with all possible phy modes which increases scan time
exponentially.
If wide band scan is enabled and scan is issues with 0 channels,
configure target to scan all available channels only in 11A/11G mode.
Change-Id: I7c678ccf43c3238aacbfc59cc7e7bd19763453cc
CRs-Fixed: 2165025
7dd49fec17