drm/amdgpu: add check for ACPI power resources

Check if the device has ACPI power resources so we can
enable runtime pm if so.
Acked-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -1024,6 +1024,7 @@ struct amdgpu_device {
 	/* enable runtime pm on the device */
 	bool                            runpm;
 	bool                            in_runpm;
+	bool                            has_pr3;
 
 	bool                            pm_sysfs_en;
 	bool                            ucode_sysfs_en;

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

@@ -133,6 +133,7 @@ void amdgpu_register_gpu_instance(struct amdgpu_device *adev)
 int amdgpu_driver_load_kms(struct amdgpu_device *adev, unsigned long flags)
 {
 	struct drm_device *dev;
+	struct pci_dev *parent;
 	int r, acpi_status;
 
 	dev = adev_to_drm(adev);
@@ -144,6 +145,9 @@ int amdgpu_driver_load_kms(struct amdgpu_device *adev, unsigned long flags)
 	    !pci_is_thunderbolt_attached(dev->pdev))
 		flags |= AMD_IS_PX;
 
+	parent = pci_upstream_bridge(adev->pdev);
+	adev->has_pr3 = parent ? pci_pr3_present(parent) : false;
+
 	/* amdgpu_device_init should report only fatal error
 	 * like memory allocation failure or iomapping failure,
 	 * or memory manager initialization failure, it must