qcacmn: Extract and populate peer_extd2 stats from fw

Presently, the driver doesnot extract the peer extended2 stats
(rx_bytes, rx_count, fcs_err) that are received from firmware.

Provide the support to extract and populate the peer extended stats2 at
the driver level.

Change-Id: If1f1bb1ef2d1202581744dd509d0da1da718d8c1
CRs-Fixed: 2397638