drm/amd/pm: correct the way for retrieving current uclk frequency

There is some problem with average frequency reading. Thus, we
switch to the target frequency reading instead.
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_0_ppt.c

@@ -840,7 +840,7 @@ static int smu_v13_0_0_read_sensor(struct smu_context *smu,
 		break;
 	case AMDGPU_PP_SENSOR_GFX_MCLK:
 		ret = smu_v13_0_0_get_smu_metrics_data(smu,
-						       METRICS_AVERAGE_UCLK,
+						       METRICS_CURR_UCLK,
 						       (uint32_t *)data);
 		*(uint32_t *)data *= 100;
 		*size = 4;