qcacld-3.0: Add support for getting cfg integer from PMO

Add support for getting cfg integer from PMO. Register callbacks
during pe_open/close so that PMO can query CFG int values for
calculating parameters like listen interval etc.

Change-Id: I52d165586576e547e175ba276e6b7225db5b27e0
CRs-Fixed: 2252661
6 files changed