agp/intel: Convert to generic power management

Convert agpgart-intel from legacy PCI power management to the generic power
management framework.

Previously agpgart-intel used legacy PCI power management, and
agp_intel_resume() was responsible for both device-specific things and
generic PCI things like saving and restoring config space and managing
power state.

In this case, agp_intel_suspend() was empty, and agp_intel_resume()
already did only device-specific things, so simply convert it to take a
struct device * instead of a struct pci_dev *.

Based on 0aeddbd0 ("via-agp: convert to generic power management") by
Vaibhav Gupta <vaibhavgupta40@gmail.com>.

Link: https://lore.kernel.org/r/20221025203852.681822-3-helgaas@kernel.orgSigned-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NDave Airlie <airlied@redhat.com>

drivers/char/agp/intel-agp.c

@@ -817,16 +817,15 @@ static void agp_intel_remove(struct pci_dev *pdev)
 	agp_put_bridge(bridge);
 }
 
-#ifdef CONFIG_PM
-static int agp_intel_resume(struct pci_dev *pdev)
+static int agp_intel_resume(struct device *dev)
 {
+	struct pci_dev *pdev = to_pci_dev(dev);
 	struct agp_bridge_data *bridge = pci_get_drvdata(pdev);
 
 	bridge->driver->configure();
 
 	return 0;
 }
-#endif
 
 static const struct pci_device_id agp_intel_pci_table[] = {
 #define ID(x)						\
@@ -895,14 +894,14 @@ static const struct pci_device_id agp_intel_pci_table[] = {
 
 MODULE_DEVICE_TABLE(pci, agp_intel_pci_table);
 
+static DEFINE_SIMPLE_DEV_PM_OPS(agp_intel_pm_ops, NULL, agp_intel_resume);
+
 static struct pci_driver agp_intel_pci_driver = {
 	.name		= "agpgart-intel",
 	.id_table	= agp_intel_pci_table,
 	.probe		= agp_intel_probe,
 	.remove		= agp_intel_remove,
-#ifdef CONFIG_PM
-	.resume		= agp_intel_resume,
-#endif
+	.driver.pm	= &agp_intel_pm_ops,
 };
 
 static int __init agp_intel_init(void)