wlan: Invoke LFR3 roaming on reception of prev_bssid in connect

When supplicant issues connect with prev_bssid set, it expects the
driver to do reassociation instead of disconnect and connect.

This fix checks if prev_bssid is set and bssid/bssid_hint, channel/
channel_hint parameters are present in connect and if yes, invokes LFR3
roaming.

Change-Id: I8d4d29086a205563061bb155a1298de91839cbec
CRs-Fixed: 2324751