usb: ohci-at91: use __maybe_unused to hide pm functions

The ohci-at91 driver uses #ifdef to check for CONFIG_PM, but then
uses SIMPLE_DEV_PM_OPS, which leaves the references out when
CONFIG_PM_SLEEP is not defined, so we get a warning with
PM=y && PM_SLEEP=n:

drivers/usb/host/ohci-at91.c:587:1: error: 'ohci_hcd_at91_drv_suspend' defined but not used [-Werror=unused-function]
drivers/usb/host/ohci-at91.c:631:12: error: 'ohci_hcd_at91_drv_resume' defined but not used [-Werror=unused-function]

This removes the incorrect #ifdef and instead uses a __maybe_unused
annotation to let the compiler know it can silently drop
the function definition.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ohci-at91.c

@@ -583,9 +583,7 @@ static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM
-
-static int
+static int __maybe_unused
 ohci_hcd_at91_drv_suspend(struct device *dev)
 {
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
@@ -630,7 +628,8 @@ ohci_hcd_at91_drv_suspend(struct device *dev)
 	return ret;
 }
 
-static int ohci_hcd_at91_drv_resume(struct device *dev)
+static int __maybe_unused
+ohci_hcd_at91_drv_resume(struct device *dev)
 {
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
 	struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
@@ -643,7 +642,6 @@ static int ohci_hcd_at91_drv_resume(struct device *dev)
 	ohci_resume(hcd, false);
 	return 0;
 }
-#endif
 
 static SIMPLE_DEV_PM_OPS(ohci_hcd_at91_pm_ops, ohci_hcd_at91_drv_suspend,
 					ohci_hcd_at91_drv_resume);