drm/radeon/dpm: implement UVD powergating for KB/KV

Powergate the UVD block when not in use to save power.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_asic.h b/drivers/gpu/drm/radeon/radeon_asic.h
index 3570817..9060757 100644
--- a/drivers/gpu/drm/radeon/radeon_asic.h
+++ b/drivers/gpu/drm/radeon/radeon_asic.h
@@ -784,5 +784,6 @@
 						    struct seq_file *m);
 int kv_dpm_force_performance_level(struct radeon_device *rdev,
 				   enum radeon_dpm_forced_level level);
+void kv_dpm_powergate_uvd(struct radeon_device *rdev, bool gate);
 
 #endif