wifi: ath12k: Support Transmit Scheduler stats

Add support to request transmission scheduler stats from firmware through
HTT stats type 4. This stat gives information such as pdev stats
scheduled per transmission queue, transmission queue command posted and
reaped, scheduler order, scheduler ineligibility and supercycle triggers.

Sample output:
-------------
echo 4 > /sys/kernel/debug/ath12k/pci-0000\:06\:00.0/mac0/htt_stats_type
cat /sys/kernel/debug/ath12k/pci-0000\:06\:00.0/mac0/htt_stats
HTT_STATS_TX_SCHED_CMN_TLV:
mac_id = 0
current_timestamp = 952546828

HTT_TX_PDEV_STATS_SCHED_PER_TXQ_TLV:
mac_id = 0
txq_id = 14
sched_policy = 2
.....

HTT_SCHED_TXQ_CMD_POSTED_TLV:
sched_cmd_posted =  0:0, 1:0, 2:0, 3:0, 4:0, 5:0, 6:0, 7:0, 8:0, 9:0,
10:0, 11:0, 12:0

HTT_SCHED_TXQ_CMD_REAPED_TLV:
sched_cmd_reaped =  0:0, 1:0, 2:0, 3:0, 4:0, 5:0, 6:0, 7:0, 8:0, 9:0,
10:0, 11:0, 12:0

HTT_SCHED_TXQ_SCHED_ORDER_SU_TLV:
sched_order_su =  0:0, 1:0, 2:0, 3:0, 4:0, 5:0, 6:0, 7:0, 8:0, 9:0, 10:0,
11:0, 12:0, 13:0, 14:0, 15:0, 16:0, 17:0, 18:0, 19:0

HTT_SCHED_TXQ_SCHED_INELIGIBILITY:
sched_ineligibility =  0:0, 1:0, 2:0, 3:0, 4:0, 5:0, 6:0, 7:0, 8:0, 9:0,
10:0, 11:0, 12:0, 13:0, 14:0, 15:0, 16:0, 17:0, 18:0, 19:0, 20:0, 21:0,
22:0, 23:0, 24:0, 25:0, 26:0, 27:0, 28:0, 29:0, 30:0, 31:0, 32:0, 33:0,
34:0, 35:0

HTT_SCHED_TXQ_SUPERCYCLE_TRIGGER:
supercycle_triggers =  0:0, 1:0, 2:0, 3:0, 4:0, 5:0, 6:0

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4

Signed-off-by: Dinesh Karthikeyan <quic_dinek@quicinc.com>
Signed-off-by: Roopni Devanathan <quic_rdevanat@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://patch.msgid.link/20240625042217.1303332-2-quic_rdevanat@quicinc.com