usb: host: xhci: remove #ifdef around PM functions

The #ifdef is slightly wrong as it doesn't cover the xhci_priv_resume_quirk()
function, causing a harmless warning:

drivers/usb/host/xhci-plat.c:58:12: error: 'xhci_priv_resume_quirk' defined but not used [-Werror=unused-function]
 static int xhci_priv_resume_quirk(struct usb_hcd *hcd)

A simpler way to do this correctly is to use __maybe_unused annotations
that let the compiler silently drop the functions when there is no
reference.

Fixes: b0c69b4 ("usb: host: plat: Enable xHCI plat runtime PM")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-plat.c

@@ -355,8 +355,7 @@ static int xhci_plat_remove(struct platform_device *dev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int xhci_plat_suspend(struct device *dev)
+static int __maybe_unused xhci_plat_suspend(struct device *dev)
 {
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
@@ -378,7 +377,7 @@ static int xhci_plat_suspend(struct device *dev)
 	return ret;
 }
 
-static int xhci_plat_resume(struct device *dev)
+static int __maybe_unused xhci_plat_resume(struct device *dev)
 {
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
@@ -393,25 +392,22 @@ static int xhci_plat_resume(struct device *dev)
 
 	return xhci_resume(xhci, 0);
 }
-#endif /* CONFIG_PM_SLEEP */
 
-#ifdef CONFIG_PM
-static int xhci_plat_runtime_suspend(struct device *dev)
+static int __maybe_unused xhci_plat_runtime_suspend(struct device *dev)
 {
 	struct usb_hcd  *hcd = dev_get_drvdata(dev);
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 
 	return xhci_suspend(xhci, true);
 }
 
-static int xhci_plat_runtime_resume(struct device *dev)
+static int __maybe_unused xhci_plat_runtime_resume(struct device *dev)
 {
 	struct usb_hcd  *hcd = dev_get_drvdata(dev);
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 
 	return xhci_resume(xhci, 0);
 }
-#endif /* CONFIG_PM */
 
 static const struct dev_pm_ops xhci_plat_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(xhci_plat_suspend, xhci_plat_resume)

drivers/usb/host/xhci.h

@@ -2004,13 +2004,8 @@ void xhci_init_driver(struct hc_driver *drv,
 int xhci_disable_slot(struct xhci_hcd *xhci,
 			struct xhci_command *command, u32 slot_id);
 
-#ifdef	CONFIG_PM
 int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup);
 int xhci_resume(struct xhci_hcd *xhci, bool hibernated);
-#else
-#define	xhci_suspend	NULL
-#define	xhci_resume	NULL
-#endif
 
 irqreturn_t xhci_irq(struct usb_hcd *hcd);
 irqreturn_t xhci_msi_irq(int irq, void *hcd);