msm: npu: Don't enable NPU while SSR is triggered

Both SSR handling and sending IPCC irq are done in worker thread.
So it's possible that when SSR is triggered but SSR handling
hasn't started, mbox worker will start first and try to enabled NPU.
But it won't succeed because NPU is in bad state. This change is to
prevent mbox worker to enable NPU in this case and also dump the
debug information when SSR is triggered.

Change-Id: I9db40b325d75b067559707c5f044a6a5fb4ed647
Signed-off-by: Jilai Wang <jilaiw@codeaurora.org>