usb: dwc3: pci: add CONFIG_PM_SLEEP to suspend/resume functions

Add CONFIG_PM_SLEEP to suspend/resume functions to fix the following
build warning when CONFIG_PM_SLEEP is not selected. This is because
sleep PM callbacks defined by SET_SYSTEM_SLEEP_PM_OPS are only used
when the CONFIG_PM_SLEEP is enabled. Unnecessary CONFIG_PM ifdefs
are removed.

drivers/usb/dwc3/dwc3-pci.c:215:12: warning: 'dwc3_pci_suspend' defined but not used [-Wunused-function]
drivers/usb/dwc3/dwc3-pci.c:224:12: warning: 'dwc3_pci_resume' defined but not used [-Wunused-function]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/dwc3-pci.c

@@ -191,7 +191,7 @@ static DEFINE_PCI_DEVICE_TABLE(dwc3_pci_id_table) = {
 };
 MODULE_DEVICE_TABLE(pci, dwc3_pci_id_table);
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 static int dwc3_pci_suspend(struct device *dev)
 {
 	struct pci_dev	*pci = to_pci_dev(dev);
@@ -216,23 +216,19 @@ static int dwc3_pci_resume(struct device *dev)
 
 	return 0;
 }
+#endif /* CONFIG_PM_SLEEP */
 
 static const struct dev_pm_ops dwc3_pci_dev_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(dwc3_pci_suspend, dwc3_pci_resume)
 };
 
-#define DEV_PM_OPS	(&dwc3_pci_dev_pm_ops)
-#else
-#define DEV_PM_OPS	NULL
-#endif /* CONFIG_PM */
-
 static struct pci_driver dwc3_pci_driver = {
 	.name		= "dwc3-pci",
 	.id_table	= dwc3_pci_id_table,
 	.probe		= dwc3_pci_probe,
 	.remove		= dwc3_pci_remove,
 	.driver		= {
-		.pm	= DEV_PM_OPS,
+		.pm	= &dwc3_pci_dev_pm_ops,
 	},
 };