agp/efficeon: Convert to generic power management

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

Previously agpgart-efficeon used legacy PCI power management, which means
agp_efficeon_suspend() and agp_efficeon_resume() were responsible for both
device-specific things and generic PCI things like saving and restoring
config space and managing power state.

In this case, agp_efficeon_suspend() was empty, and agp_efficeon_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/20221025203852.681822-2-helgaas@kernel.orgSigned-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NDave Airlie <airlied@redhat.com>

drivers/char/agp/efficeon-agp.c

@@ -412,18 +412,11 @@ static void agp_efficeon_remove(struct pci_dev *pdev)
 	agp_put_bridge(bridge);
 }
 
-#ifdef CONFIG_PM
-static int agp_efficeon_suspend(struct pci_dev *dev, pm_message_t state)
-{
-	return 0;
-}
-
-static int agp_efficeon_resume(struct pci_dev *pdev)
+static int agp_efficeon_resume(struct device *dev)
 {
 	printk(KERN_DEBUG PFX "agp_efficeon_resume()\n");
 	return efficeon_configure();
 }
-#endif
 
 static const struct pci_device_id agp_efficeon_pci_table[] = {
 	{
@@ -437,6 +430,8 @@ static const struct pci_device_id agp_efficeon_pci_table[] = {
 	{ }
 };
 
+static DEFINE_SIMPLE_DEV_PM_OPS(agp_efficeon_pm_ops, NULL, agp_efficeon_resume);
+
 MODULE_DEVICE_TABLE(pci, agp_efficeon_pci_table);
 
 static struct pci_driver agp_efficeon_pci_driver = {
@@ -444,10 +439,7 @@ static struct pci_driver agp_efficeon_pci_driver = {
 	.id_table	= agp_efficeon_pci_table,
 	.probe		= agp_efficeon_probe,
 	.remove		= agp_efficeon_remove,
-#ifdef CONFIG_PM
-	.suspend	= agp_efficeon_suspend,
-	.resume		= agp_efficeon_resume,
-#endif
+	.driver.pm	= &agp_efficeon_pm_ops,
 };
 
 static int __init agp_efficeon_init(void)