agp/amd64: Update to DEFINE_SIMPLE_DEV_PM_OPS()

As of 1a3c7bb088 ("PM: core: Add new *_PM_OPS macros, deprecate old
ones"), SIMPLE_DEV_PM_OPS() is deprecated in favor of
DEFINE_SIMPLE_DEV_PM_OPS(), which has the advantage that the PM callbacks
don't need to be wrapped with #ifdef CONFIG_PM or tagged with
__maybe_unused.

Convert to DEFINE_SIMPLE_DEV_PM_OPS().  No functional change intended.

Link: https://lore.kernel.org/r/20221025203852.681822-7-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Dave Airlie <airlied@redhat.com>

drivers/char/agp/amd64-agp.c

@@ -588,9 +588,7 @@ static void agp_amd64_remove(struct pci_dev *pdev)
 	agp_bridges_found--;
 }
 
-#define agp_amd64_suspend NULL
-
-static int __maybe_unused agp_amd64_resume(struct device *dev)
+static int agp_amd64_resume(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 
@@ -727,7 +725,7 @@ static const struct pci_device_id agp_amd64_pci_promisc_table[] = {
 	{ }
 };
 
-static SIMPLE_DEV_PM_OPS(agp_amd64_pm_ops, agp_amd64_suspend, agp_amd64_resume);
+static DEFINE_SIMPLE_DEV_PM_OPS(agp_amd64_pm_ops, NULL, agp_amd64_resume);
 
 static struct pci_driver agp_amd64_pci_driver = {
 	.name		= "agpgart-amd64",