drm/nouveau/pmu: add msgqueue member

NVIDIA-provided PMU firmware is controlled by a msgqueue. Add a member
to the PMU structure as well as the required cleanup code if this
feature is used.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2 files changed