wifi: ath12k: Rename ath12k_peer to ath12k_dp_link_peer

wifi: ath12k: Rename ath12k_peer to ath12k_dp_link_peer

Rename ath12k_peer to ath12k_dp_link_peer for all instances and rename the
following find APIs accordingly to reflect the API names as per the structural
name change.

APIs renamed:
  ath12k_peer_find()
  ath12k_peer_find_by_pdev_idx()
  ath12k_peer_find_by_addr()
  ath12k_peer_find_by_ml_id()
  ath12k_peer_find_by_id()
  ath12k_peer_find_by_ast()
  ath12k_peer_exist_by_vdev_id()
  ath12k_peer_get_link_sta()

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Signed-off-by: Harsh Kumar Bijlani <quic_hbijlani@quicinc.com>
Signed-off-by: Ripan Deuri <quic_rdeuri@quicinc.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Link: https://patch.msgid.link/20251024181548.3255166-3-quic_rdeuri@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>