qcacld-3.0: Remove unused function hdd_get_peer_idx

Currently the function hdd_get_peer_idx is not being called from
anywhere. As the use of sta_id is being depreceted, the function can be
safely removed.

Clean up the unused function.

Change-Id: I6896d03ad2e8b427147e2259b737836cd3f44ca0
CRs-Fixed: 2484699
2 files changed