qcacmn: Add only frames with valid channel in scan cache

Kernel reject the beacon/probe resp frame with invalid channel in
DS,HT info and HE IE, but same frame is added in the scan cache
and when mlme refer this frame, connect issues are seen due to
invalid channel.

Thus do not add the entry in scan cache.

Change-Id: Ib2891f95034b04be26c5feefed7c4354d8bb367a
CRs-Fixed: 2708975