wlan: Fix FT roaming failure issue

Currently, driver invokes csrRoamOffloadScan with command
ROAM_SCAN_OFFLOAD_STOP to handle offload scan req and subsequently
invokes CsrIsRSOCommandAllowed to check whether RSO stop command can
be send down to firmware or not. If RSO is in a stopped state
CsrIsRSOCommandAllowed does not allow CSR handoff request.
This results in FT roaming failure.

This change introduces change to allow the driver to invoke
csrNeighborRoamProceedWithHandoffReq and proceed with roaming 
handoff req if RSO is in a stopped state.

Change-Id: Ic80583dca92c4f3af1949df3303b77b4f055c4ca
CRs-Fixed: 2324819