wifi: ath12k: Rearrange DP fields in ath12k_hw_group struct

wifi: ath12k: Rearrange DP fields in ath12k_hw_group struct

Introduce the ath12k_dp_hw_group struct within ath12k_hw_group to
encapsulate all Data Path fields, providing a baseline for future
extensions. Add this struct to the top of ath12k_hw_group to allow
optimal usage of cache lines for data path fields, as it is accessed
in multiple tight loops in the per-packet path.

Add cmn_def.h to define common macros shared between DP and other
modules.

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: 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/20250930131005.2884253-4-quic_rdeuri@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>