ath10k:  provide firmware crash info via debugfs.

Store the firmware crash registers and last 128 or so
firmware debug-log ids and present them to user-space
via debugfs.

Should help with figuring out why the firmware crashed.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
ath10k:  save firmware debug log messages.

They may be dumped through the firmware dump debugfs
file.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
ath10k:  save firmware stack upon firmware crash.

Should help debug firmware crashes, and give users a way
to provide some useful debug reports to firmware developers.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
ath10k: Dump exception stack contents on firmware crash.

Firmware developers can decode this and maybe figure out
why the firmware crashed.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>