wifi: ath12k: add support for collecting firmware log

Currently there is no way to collect firmware log because firmware
does not send it to host. Also host does not handle WMI_DIAG_EVENTID
which is used by firmware to upload firmware log.

So add support for it by firstly enabling firmware log upload via a
QMI message, and secondly processing WMI DIAG event to expose it to
userspace via trace event.

This change applies to both WCN7850 and QCN9274.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4

Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20240115023726.2866-1-quic_bqiang@quicinc.com