scsi: hpsa: Use generic power management

Drivers should do only device-specific jobs. But in general, drivers using
legacy PCI PM framework for .suspend()/.resume() have to manage many PCI
PM-related tasks themselves which can be done by PCI Core itself. This
brings extra load on the driver and it directly calls PCI helper functions
to handle them.

Switch to the new generic framework by updating function signatures and
define a "struct dev_pm_ops" variable to bind PM callbacks. Also, remove
unnecessary calls to the PCI Helper functions along with the legacy
.suspend & .resume bindings.

Link: https://lore.kernel.org/r/20201102164730.324035-21-vaibhavgupta40@gmail.comAcked-by: Don Brace <don.brace@microchip.com>
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hpsa.c

@@ -9079,25 +9079,27 @@ static void hpsa_remove_one(struct pci_dev *pdev)
 	hpda_free_ctlr_info(h);				/* init_one 1 */
 }
 
-static int hpsa_suspend(__attribute__((unused)) struct pci_dev *pdev,
-	__attribute__((unused)) pm_message_t state)
+static int __maybe_unused hpsa_suspend(
+	__attribute__((unused)) struct device *dev)
 {
 	return -ENOSYS;
 }
 
-static int hpsa_resume(__attribute__((unused)) struct pci_dev *pdev)
+static int __maybe_unused hpsa_resume
+	(__attribute__((unused)) struct device *dev)
 {
 	return -ENOSYS;
 }
 
+static SIMPLE_DEV_PM_OPS(hpsa_pm_ops, hpsa_suspend, hpsa_resume);
+
 static struct pci_driver hpsa_pci_driver = {
 	.name = HPSA,
 	.probe = hpsa_init_one,
 	.remove = hpsa_remove_one,
 	.id_table = hpsa_pci_device_id,	/* id_table */
 	.shutdown = hpsa_shutdown,
-	.suspend = hpsa_suspend,
-	.resume = hpsa_resume,
+	.driver.pm = &hpsa_pm_ops,
 };
 
 /* Fill in bucket_map[], given nsgs (the max number of