qcacld-3.0: Remove ValidChannelList from tSirRoamOffloadScanReq
The separate ValidChannelList & ValidChannelCount fields in
tSirRoamOffloadScanReq are obsolete since the valid channels are now
handled as part of the ConnectedNetwork struct, therefore remove
support for these obsolete fields.
Change-Id: Ic413d52f95fcc7082e1dfdd28d28513d6a7a2e7d
CRs-Fixed: 2370961