qcacmn: Restrict dwell time only if SAP/GO is connected

Currently, in case of SAP/GO present active dwell time of scan req
on STA iface is restricted. This can result in less scan time but
STA can miss some AP's. So, decrease dwell time only if some client
is connected to SAP or GO.

Change-Id: I46fb76792941b7c79f541b8b358d02bb944f0086
CRs-Fixed: 2436910