drm/amd/powerplay: correct Navi10 VCN powergate control (v2)

No VCN DPM bit check as that's different from VCN PG. Also
no extra check for possible double enablement/disablement
as that's already done by VCN.

v2: check return value of smu_feature_set_enabled
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/powerplay/navi10_ppt.c

@@ -592,28 +592,20 @@ static int navi10_set_default_dpm_table(struct smu_context *smu)
 static int navi10_dpm_set_uvd_enable(struct smu_context *smu, bool enable)
 {
 	int ret = 0;
-	struct smu_power_context *smu_power = &smu->smu_power;
-	struct smu_power_gate *power_gate = &smu_power->power_gate;
 
-	if (enable && power_gate->uvd_gated) {
-		if (smu_feature_is_enabled(smu, SMU_FEATURE_DPM_UVD_BIT)) {
+	if (enable) {
 		ret = smu_send_smc_msg_with_param(smu, SMU_MSG_PowerUpVcn, 1);
 		if (ret)
 			return ret;
-		}
-		power_gate->uvd_gated = false;
 	} else {
-		if (!enable && !power_gate->uvd_gated) {
-			if (smu_feature_is_enabled(smu, SMU_FEATURE_DPM_UVD_BIT)) {
 		ret = smu_send_smc_msg(smu, SMU_MSG_PowerDownVcn);
 		if (ret)
 			return ret;
 	}
-			power_gate->uvd_gated = true;
-		}
-	}
 
-	return 0;
+	ret = smu_feature_set_enabled(smu, SMU_FEATURE_VCN_PG_BIT, enable);
+
+	return ret;
 }
 
 static int navi10_get_current_clk_freq_by_table(struct smu_context *smu,