Currently as long as STA connection is present on DFS channel, host
driver doesn't trim 5 GHz channel lists even if there has SAP on DFS
channel. But for DBS capability chips, like Hasting, when DFS SAP is
present, it's still not allowed to do scan even if STA DFS connection
is available. If don't trim 5 GHz channel lists, the result is that
FW will return cancelled status for the last scan event of the DFS
BSS channel. So host driver would return aborted status even if 2.4
GHz channels can be normally scanned and upper layer cannot get any
scan results.
Change-Id: I885dbccd9beb8bc1c4956c89d90d33cda2bc301d
CRs-Fixed: 3274000