qcacld-3.0: Use acs scan request timestamp in scan req

Currently the driver flushes all the scan results during
ACS request, and then scans the specific channels as
mentioned in the request, which leads to a scan again
for the STA interface as no scan results are available.

Fix is to have a timestamp, and get only the latest scan
results, instead of the scan database flush.

Change-Id: Icc343fcca77fb7074071ca1d467947ef70fd1930
CRs-Fixed: 2446490
5 files changed