drm/amd/powerplay: add new sensor type for VCN powergate status

VCN is widely used in new ASICs and different from tranditional
UVD and VCE.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/include/kgd_pp_interface.h

@@ -123,6 +123,7 @@ enum amd_pp_sensors {
 	AMDGPU_PP_SENSOR_ENABLED_SMC_FEATURES_MASK,
 	AMDGPU_PP_SENSOR_MIN_FAN_RPM,
 	AMDGPU_PP_SENSOR_MAX_FAN_RPM,
+	AMDGPU_PP_SENSOR_VCN_POWER_STATE,
 };
 
 enum amd_pp_task {