remoteproc: qcom_q6v5: Introduce panic handler for MSS

Make the MSS q6v5 remoteproc drivers implement the panic handler
that will invoke a stop to prepare the remoteprocs for post mortem
debugging.

Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1653396335-6295-3-git-send-email-quic_sibis@quicinc.com