ath10k: Add WMI diag fw logging support for WCN3990

ath10k: Add WMI diag fw logging support for WCN3990

Integrated WiFi chipset ex:WCN399x supports fw logging
using WMI copy engine and shared mem DIAG based fw logging.
By default shared mem DIAG based fw logging is enabled.
To support WMI copy engine based fw logging add QMI
control message to enable WMI copy engine based fw logging.

Enable WMI based fw logging using fw_diag_log module parameter.

insmod ath10k_core.ko fw_diag_log=1

DIAG utility(https://github.com/andersson/diag) implements extraction
of diagnostics related messages between application processor and
various subsystems while shared mem DIAG based fw logging is enabled.

Testing: Tested on WCN3990/QCA6174 HW
Tested FW: WLAN.HL.3.1-00959-QCAHLSWMTPLZ-1

Signed-off-by: Govind Singh <govinds@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>