prima: Restrict the split scan to SAP

Currently, split scan is used in case of STA + SAP.
But SAP presence is checked by the api csrIsInfraApStarted
which is true for both SAP and GO.
Because of this scan duration is affected when GO is present.

In case of GO, split scan should be controlled by ini
gNumP2PChanCombinedConc

Use split scan for SAP and for GO take the decision based on 
ini gNumP2PChanCombinedConc.

Change-Id: I3b0ac5d5f0dba74de53edd86aaf63bd67de91061
CRs-Fixed: 2398730