wifi: ath12k: add thermal cooling device support

wifi: ath12k: add thermal cooling device support

Add thermal cooling device support to control the temperature by throttling data
transmission. Throttling is performed by suspending data TX queues according to
a configured duty-cycle off percentage. The thermal cooling device allows users
to configure the duty-cycle off percentage and operate the device with the
selected value.

User configuration updates a single duty-cycle off percentage, which is applied
uniformly by the host and treated as only one temperature level. This value
remains in effect until updated again by the user. All other thermal throttling
parameters continue to use their default firmware provided values.

Reject invalid duty-cycle off percentage values that fall outside the supported
range. Register a cooling device to allow the thermal framework to query and set
the current throttle state, report the maximum supported state, and keep the
host state in sync with successful firmware updates. A throttle state of zero
restores the default firmware thermal configuration.

Command to set the duty-cycle off percent:
echo 40 > /sys/devices/pci0000:00/0000:00:1d.1/0000:58:00.0/ieee80211/phyX/cooling_device0/cur_state

Command to read duty-cycle off percent:
cat /sys/devices/pci0000:00/0000:00:1d.1/0000:58:00.0/ieee80211/phyX/cooling_device0/cur_state

Command to read the maximum duty-cycle off percent:
cat /sys/devices/pci0000:00/0000:00:1d.1/0000:58:00.0/ieee80211/phyX/cooling_device0/max_state

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6-01243-QCAHKSWPL_SILICONZ-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3

Signed-off-by: Maharaja Kennadyrajan <maharaja.kennadyrajan@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Link: https://patch.msgid.link/20260413153840.1969931-6-maharaja.kennadyrajan@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>