drm/amdgpu/cz: add code to enable forcing UVD clocks

UVD DPM works similarly to SCLK DPM.  Add a similar interface
for UVD for forcing the UVD clocks.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/cz_dpm.h b/drivers/gpu/drm/amd/amdgpu/cz_dpm.h
index 99e1afc..6a6a6fe 100644
--- a/drivers/gpu/drm/amd/amdgpu/cz_dpm.h
+++ b/drivers/gpu/drm/amd/amdgpu/cz_dpm.h
@@ -183,6 +183,7 @@
 	uint32_t voltage_drop_threshold;
 	uint32_t gfx_pg_threshold;
 	uint32_t max_sclk_level;
+	uint32_t max_uvd_level;
 	/* flags */
 	bool didt_enabled;
 	bool video_start;