rtc: xgene: mark PM functions as __maybe_unused

The new xgene_rtc_alarm_irq_enabled() function is only accessed
from PM code, which is inside of an #ifdef; this causes a harmless
build warning when CONFIG_PM is disabled:

drivers/rtc/rtc-xgene.c:108:12: error: 'xgene_rtc_alarm_irq_enabled' defined but not used [-Werror=unused-function]

Just remove the #ifdef and use __maybe_unused annotations instead,
to make the code more robust here.

Fixes: d0bcd82b ("rtc: xgene: Fix suspend/resume")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Loc Ho <lho@apm.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/rtc-xgene.c

@@ -221,8 +221,7 @@ static int xgene_rtc_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int xgene_rtc_suspend(struct device *dev)
+static int __maybe_unused xgene_rtc_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct xgene_rtc_dev *pdata = platform_get_drvdata(pdev);
@@ -246,7 +245,7 @@ static int xgene_rtc_suspend(struct device *dev)
 	return 0;
 }
 
-static int xgene_rtc_resume(struct device *dev)
+static int __maybe_unused xgene_rtc_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct xgene_rtc_dev *pdata = platform_get_drvdata(pdev);
@@ -271,7 +270,6 @@ static int xgene_rtc_resume(struct device *dev)
 
 	return 0;
 }
-#endif
 
 static SIMPLE_DEV_PM_OPS(xgene_rtc_pm_ops, xgene_rtc_suspend, xgene_rtc_resume);