wifi: ath12k: Add support for link specific datapath stats

wifi: ath12k: Add support for link specific datapath stats

Add support to record the number of frames enqueued, hardware
descriptor type, encapsulation/encryption types used, frames
dropped and completed. This is useful for understanding the
datapath performance and tune the peak throughput.

The link specific stats can be viewed through the below debugfs file

cat /sys/kernel/debug/ieee80211/phy0/netdev:wlan1/link_stats
link[0] Tx Unicast Frames Enqueued  = 9
link[0] Tx Broadcast Frames Enqueued = 78689
link[0] Tx Frames Completed = 78698
link[0] Tx Frames Dropped = 0
link[0] Tx Frame descriptor Encap Type =  raw:0 native wifi:78698 ethernet:0
link[0] Tx Frame descriptor Encrypt Type =  0:78698 1:0 2:0 3:0 4:0 5:0 6:0 7:0 8:0 9:0 10:0 11:0
link[0] Tx Frame descriptor Type = buffer:78698 extension:0
------------------------------------------------------
link[1] Tx Unicast Frames Enqueued  = 0
link[1] Tx Broadcast Frames Enqueued = 78689
link[1] Tx Frames Completed = 78689
link[1] Tx Frames Dropped = 0
link[1] Tx Frame descriptor Encap Type =  raw:0 native wifi:78689 ethernet:0
link[1] Tx Frame descriptor Encrypt Type =  0:78689 1:0 2:0 3:0 4:0 5:0 6:0 7:0 8:0 9:0 10:0 11:0
link[1] Tx Frame descriptor Type = buffer:78689 extension:0
------------------------------------------------------

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-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: Balamurugan Mahalingam <quic_bmahalin@quicinc.com>
Link: https://patch.msgid.link/20250409155125.299380-1-quic_bmahalin@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>