gpio: mxc: Improve PM configuration

If CONFIG_PM=n (e.g. m68k/allmodconfig):

    drivers/gpio/gpio-mxc.c:612:12: error: ‘mxc_gpio_runtime_resume’ defined but not used [-Werror=unused-function]
      612 | static int mxc_gpio_runtime_resume(struct device *dev)
          |            ^~~~~~~~~~~~~~~~~~~~~~~
    drivers/gpio/gpio-mxc.c:602:12: error: ‘mxc_gpio_runtime_suspend’ defined but not used [-Werror=unused-function]
      602 | static int mxc_gpio_runtime_suspend(struct device *dev)
          |            ^~~~~~~~~~~~~~~~~~~~~~~~

Fix this by using the non-SET *_PM_OPS to configure the dev_pm_ops
callbacks, and by wrapping the driver.pm initializer insider pm_ptr().

As NOIRQ_SYSTEM_SLEEP_PM_OPS() uses pm_sleep_ptr() internally, the
__maybe_unused annotations for the noirq callbacks are no longer needed,
and can be removed.

Fixes: 3283d820 ("gpio: mxc: add runtime pm support")
Reported-by: noreply@ellerman.id.au
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpio-mxc.c

@@ -622,7 +622,7 @@ static int mxc_gpio_runtime_resume(struct device *dev)
 	return 0;
 }
 
-static int __maybe_unused mxc_gpio_noirq_suspend(struct device *dev)
+static int mxc_gpio_noirq_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct mxc_gpio_port *port = platform_get_drvdata(pdev);
@@ -633,7 +633,7 @@ static int __maybe_unused mxc_gpio_noirq_suspend(struct device *dev)
 	return 0;
 }
 
-static int __maybe_unused mxc_gpio_noirq_resume(struct device *dev)
+static int mxc_gpio_noirq_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct mxc_gpio_port *port = platform_get_drvdata(pdev);
@@ -646,8 +646,8 @@ static int __maybe_unused mxc_gpio_noirq_resume(struct device *dev)
 }
 
 static const struct dev_pm_ops mxc_gpio_dev_pm_ops = {
-	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mxc_gpio_noirq_suspend, mxc_gpio_noirq_resume)
-	SET_RUNTIME_PM_OPS(mxc_gpio_runtime_suspend, mxc_gpio_runtime_resume, NULL)
+	NOIRQ_SYSTEM_SLEEP_PM_OPS(mxc_gpio_noirq_suspend, mxc_gpio_noirq_resume)
+	RUNTIME_PM_OPS(mxc_gpio_runtime_suspend, mxc_gpio_runtime_resume, NULL)
 };
 
 static int mxc_gpio_syscore_suspend(void)
@@ -694,7 +694,7 @@ static struct platform_driver mxc_gpio_driver = {
 		.name	= "gpio-mxc",
 		.of_match_table = mxc_gpio_dt_ids,
 		.suppress_bind_attrs = true,
-		.pm = &mxc_gpio_dev_pm_ops,
+		.pm = pm_ptr(&mxc_gpio_dev_pm_ops),
 	},
 	.probe		= mxc_gpio_probe,
 };