drm/nouveau/debugfs: Wake up GPU before doing any reclocking

[ Upstream commit eaeb9010bb4bcdc20e58254fa42f3fe730a7f908 ]

Fixes various reclocking related issues on prime systems.

Signed-off-by: Karol Herbst <karolherbst@gmail.com>
Signed-off-by: Martin Peres <martin.peres@free.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>