drm/amdgpu: only check for _PR3 on dGPUs

We don't support runtime pm on APUs.  They support more
dynamic power savings using clock and powergating.
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -2159,8 +2159,10 @@ static int amdgpu_device_ip_early_init(struct amdgpu_device *adev)
 	    !pci_is_thunderbolt_attached(to_pci_dev(dev->dev)))
 		adev->flags |= AMD_IS_PX;
 
+	if (!(adev->flags & AMD_IS_APU)) {
 		parent = pci_upstream_bridge(adev->pdev);
 		adev->has_pr3 = parent ? pci_pr3_present(parent) : false;
+	}
 
 	amdgpu_amdkfd_device_probe(adev);