preliminary: Don't fail TestWorkThroughput when only one frequency
preliminary: Don't fail TestWorkThroughput when only one frequency

arnoldlu/lisa,arnoldlu/lisa,bjackman/lisa,credp/lisa,ARM-software/lisa,bjackman/lisa,ARM-software/lisa,ARM-software/lisa,joelagnel/lisa,ARM-software/lisa,credp/lisa,credp/lisa,credp/lisa,joelagnel/lisa,mdigiorgio/lisa,mdigiorgio/lisa