qcacld-3.0: Use freq hint in scan for ssid

When Scan db reaches max size, driver deletes the oldest node,
so chances are that BSS on 1st freq scanned is removed.

This lead to scan for SSID, which will do a scan again on
all freqs, and thus we end up in flushing the entry again.

TO fix this use freq hint to scan for ssid to quickly find the
AP so that required AP remains in scan database as it will
be the latest entry.

Change-Id: I28849ee97ff1f492d372870c362288206c4ec9a5
CRs-Fixed: 3391899