wifi: ath12k: Move DP device stats to ath12k_dp

wifi: ath12k: Move DP device stats to ath12k_dp

As part of data path modularization of device object framework, the per packet
tx/rx operations now use ath12k_dp. Move all the device stats 'device_stats'
from ath12k_base to ath12k_dp, consolidating all device stats within ath12k_dp.
This would improve the performance by allowing the datapath to reach to the
stats counters without to having to reach out to ath12k_base object.

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: Pavankumar Nandeshwar <quic_pnandesh@quicinc.com>
Signed-off-by: Ripan Deuri <quic_rdeuri@quicinc.com>
Reviewed-by: Karthikeyan Periyasamy <karthikeyan.periyasamy@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Link: https://patch.msgid.link/20251103112111.2260639-3-quic_rdeuri@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>