drm/gma500: Add hooks for hibernation

Currently we do whatever is done during suspend/resume but we might need some
more work for hibernation so keep them in separate functions.

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
diff --git a/drivers/gpu/drm/gma500/power.h b/drivers/gpu/drm/gma500/power.h
index 1969d2e..56d8708 100644
--- a/drivers/gpu/drm/gma500/power.h
+++ b/drivers/gpu/drm/gma500/power.h
@@ -41,6 +41,9 @@
  */
 int gma_power_suspend(struct device *dev);
 int gma_power_resume(struct device *dev);
+int gma_power_thaw(struct device *dev);
+int gma_power_freeze(struct device *dev);
+int gma_power_restore(struct device *_dev);
 
 /*
  * These are the functions the driver should use to wrap all hw access