FW triggers roaming based on the RSSI score of AP(s) available
after background scan. Currently, the host does not configure
the value of bg_rssi_threshold RSSI. This results in ping-pong
roaming after background scan, even though candidate AP
RSSI is not better than 5dbm than connected AP.
Fix is to configure the value of bg_rssi_threshold via new
INI "bg_rssi_threshold" and configuring default value of
INI as 5dB.
Min: 0
Max: 100
Default: 5
Change-Id: Ib710e294c8b33ff4903d41453e3b55f02daf53ae
CRs-Fixed: 2763962