linux-phytec-ti

drm/nouveau/pm: prevent freeing the wrong engine context

This fixes a crash when multiple PM engine contexts are created.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Martin Peres <martin.peres@free.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>