kernel/panic: Show the stacktrace after additional notifier messages

Most systems keep the last messages from the panic, and we value the
stacktrace most, so dump it last in order to preserve it for
post-mortems.

References: https://gitlab.freedesktop.org/drm/intel/-/issues/8030


Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Martin Peres <martin.peres@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180903131745.30593-1-chris@chris-wilson.co.uk


Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>