nouveau: add a third state to the fini handler.

nouveau: add a third state to the fini handler.

This is just refactoring to allow the lower layers to distinguish
between suspend and runtime suspend.

GSP 570 needs to set a flag with the GPU is going into GCOFF,
this flag taken from the opengpu driver is set whenever runtime
suspend is enterning GCOFF but not for normal suspend paths.

This just refactors the code, a subsequent patch use the information.

Fixes: 53dac0623853 ("drm/nouveau/gsp: add support for 570.144")
Cc: <stable@vger.kernel.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Tested-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patch.msgid.link/20260203052431.2219998-3-airlied@gmail.com