watchdog: mtk_wdt: Remove #ifdef guards for PM related functions

Use the new DEFINE_SIMPLE_DEV_PM_OPS() and pm_sleep_ptr() macros to
handle the .suspend/.resume callbacks.

These macros allow the suspend and resume functions to be automatically
dropped by the compiler when CONFIG_SUSPEND is disabled, without having
to use #ifdef guards. Not using #ifdef guards means that the code is
always compiled independently of any Kconfig option, and thanks to that
bugs and regressions are easier to catch.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220628193449.160585-4-paul@crapouillou.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/mtk_wdt.c

@@ -401,7 +401,6 @@ static int mtk_wdt_probe(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int mtk_wdt_suspend(struct device *dev)
 {
 	struct mtk_wdt_dev *mtk_wdt = dev_get_drvdata(dev);
@@ -423,7 +422,6 @@ static int mtk_wdt_resume(struct device *dev)
 
 	return 0;
 }
-#endif
 
 static const struct of_device_id mtk_wdt_dt_ids[] = {
 	{ .compatible = "mediatek,mt2712-wdt", .data = &mt2712_data },
@@ -437,16 +435,14 @@ static const struct of_device_id mtk_wdt_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
 
-static const struct dev_pm_ops mtk_wdt_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(mtk_wdt_suspend,
-				mtk_wdt_resume)
-};
+static DEFINE_SIMPLE_DEV_PM_OPS(mtk_wdt_pm_ops,
+				mtk_wdt_suspend, mtk_wdt_resume);
 
 static struct platform_driver mtk_wdt_driver = {
 	.probe		= mtk_wdt_probe,
 	.driver		= {
 		.name		= DRV_NAME,
-		.pm		= &mtk_wdt_pm_ops,
+		.pm		= pm_sleep_ptr(&mtk_wdt_pm_ops),
 		.of_match_table	= mtk_wdt_dt_ids,
 	},
 };