wifi: ath12k: Move DP related functions from peer.c to dp_peer.c file

wifi: ath12k: Move DP related functions from peer.c to dp_peer.c file

Refactor the structures and APIs defined in files peer.h and peer.c in such a
way that the APIs making use of ath12k_peer are moved to newly introduced files
dp_peer.h and dp_peer.c.

Have this new file dp_peer.c compiled as part of kernel module ath12k.ko.

Move these APIs from peer.h and peer.c to dp_peer.h and dp_peer.c:
  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_exist_by_vdev_id()
  ath12k_peer_find_by_ast()
  ath12k_peer_unmap_event()
  ath12k_peer_map_event()
  ath12k_peer_get_link_sta()

Background:

In current ath12k architecture, connected station is represented by struct
ath12k_sta.

struct ath12k_sta has an array of struct ath12k_link_sta wherein each index
represents one link of the connected station.

For each ath12k_link_sta, there is a corresponding data path peer which is
represented by struct ath12k_peer.

Diagrammatic view of the station is as below:

        ath12k_sta
            |
            |-> ath12k_link_sta <--> ath12k_peer
            |
            |-> ath12k_link_sta <--> ath12k_peer
            |
            |-> ath12k_link_sta <--> ath12k_peer

Currently, in control path, ath12k_link_sta and ath12k_peer are used
interchangeably, while the data path makes use of ath12k_peer only.

For ath12k next-generation driver framework, in order to have a clean
segregation between control and data path, use ath12k_link_sta only for control
path operations.

Station view for the data path is revamped as below:

        ath12k_dp_peer
               |
               |-> ath12k_dp_link_peer
               |
               |-> ath12k_dp_link_peer
               |
               |-> ath12k_dp_link_peer

Introduce the structure ath12k_dp_peer to represent the data path version of
corresponding ath12k_sta.

This ath12k_dp_peer contains the fields used in the per packet Tx Rx paths
applicable across all the links and maintains an array of ath12k_dp_link_peer.
Per packet Tx and Rx path operates on ath12k_dp_peer. This ath12k_dp_peer is a
standalone new object and has back pointer reference to ieee80211_sta.

Rename ath12k_peer to ath12k_dp_link_peer and move the fields which are common
across all the links to ath12k_dp_peer.

Add the fields specific to a link which are mostly for statistics and monitor
usage to ath12k_dp_link_peer.

Final view of station in ath12k next-generation driver is shown as below:

            Control Path                            Data Path
        -------------------------------------------------------------------
        ath12k_sta                            ath12k_dp_peer
            |                                       |
            |-> ath12k_link_sta    <---->           |-> ath12k_dp_link_peer
            |                                       |
            |-> ath12k_link_sta    <---->           |-> ath12k_dp_link_peer
            |                                       |
            |-> ath12k_link_sta    <---->           |-> ath12k_dp_link_peer

This patch and the subsequent patches in this series are meant to achieve the
modularization of peer object as mentioned above.

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/20251024181548.3255166-2-quic_rdeuri@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>