drm/nv40/pm: write nv40-specific reclocking routines

Not 100% perfect yet, but a good start towards what it'll look like in the
end.

Actually seems stable on a NV44 I have here, as much as running around OA
for a fair amount of time constantly switching between performance levels
can prove..

My NV49 isn't quite so happy, and semaphores mess up somehow (sometimes) as
a result of the memory reclocking.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_pm.h b/drivers/gpu/drm/nouveau/nouveau_pm.h
index f519883..8ac02cd 100644
--- a/drivers/gpu/drm/nouveau/nouveau_pm.h
+++ b/drivers/gpu/drm/nouveau/nouveau_pm.h
@@ -52,6 +52,11 @@
 			u32 id, int khz);
 void nv04_pm_clock_set(struct drm_device *, void *);
 
+/* nv40_pm.c */
+int nv40_pm_clocks_get(struct drm_device *, struct nouveau_pm_level *);
+void *nv40_pm_clocks_pre(struct drm_device *, struct nouveau_pm_level *);
+void nv40_pm_clocks_set(struct drm_device *, void *);
+
 /* nv50_pm.c */
 int nv50_pm_clock_get(struct drm_device *, u32 id);
 void *nv50_pm_clock_pre(struct drm_device *, struct nouveau_pm_level *,