decouple SW FLP and HW FLP overlay flags

currently there is only overlay flag shared by SW FLP and HW FLP. This
change allows having different overlay setting for sw / hw FLPs.

Change-Id: I643fa70380e7568ae851d23e87917a5b4b599fe8
CRs-Fixed: 622338
Merge "decouple SW FLP and HW FLP overlay flags" into kk4.4