drm/amd/powerplay: update is_sw_smu_xgmi check

Add check for is_sw_smu routine and drop check
for amdgpu_dpm which seems non-sense.

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

drivers/gpu/drm/amd/powerplay/amdgpu_smu.c

@@ -526,7 +526,7 @@ bool is_support_sw_smu(struct amdgpu_device *adev)
 
 bool is_support_sw_smu_xgmi(struct amdgpu_device *adev)
 {
-	if (amdgpu_dpm != 1)
+	if (!is_support_sw_smu(adev))
 		return false;
 
 	if (adev->asic_type == CHIP_VEGA20)