ath10k: fix hw-restart crash inject mode for WCN3990

The hw-restart crash inject mode is a special mode, where
there is no crash generated in the firmware, but instead
the driver restarts the firmware. In order to restart WCN3990
firmware, the driver needs to send qmi_wlan_disable message
followed by the qmi_wlan_enable message to the WCN3990 firmware.

Currently the qmi_wlan_disable message is not sent to
the WCN3990 firmware when hw-restart crash is injected,
which causes the firmware to crash when the driver sends
qmi_wlan_enable message during ath10k_restart.

Send qmi_wlan_disable to the WCN3990 firmware when the
hw-restart crash is injected via debugfs.

Tested HW: WCN3990
Tested FW: WLAN.HL.2.0-01188-QCAHLSWMTPLZ-1

Signed-off-by: Rakesh Pillai <pillair@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>