qcacmn: Add 2G channel active dwell time CFG/INI items

Add ini item to configure active dwell time of 2.4GHz band channels,
This will help to reduce AP search failure probability & hence
connection latency in 2.4GHz band channels especially in noisy
condition by increasing active dwell time.

Change-Id: I05259a8f1fd4a5c67da42e516721a01d32fa652e
CRs-Fixed: 2283692
5 files changed