remoteproc: qcom: q6v5: Query sysmon before graceful shutdown

remoteproc: qcom: q6v5: Query sysmon before graceful shutdown

Requesting a graceful shutdown through the shared memory state signals
will not be acked in the event that sysmon has already successfully shut
down the remote firmware. So extend the stop request API to optionally
take the remoteproc's sysmon instance and query if there's already been
a successful shutdown attempt, before doing the signal dance.

Tested-by: Steev Klimaszewski <steev@kali.org>
Reviewed-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Link: https://lore.kernel.org/r/20201122054135.802935-4-bjorn.andersson@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>