gpio: xgene: mark PM functions as __maybe_unused

When CONFIG_PM_SLEEP is disabled, we get a warning about unused functions:

drivers/gpio/gpio-xgene.c:155:12: warning: 'xgene_gpio_resume' defined but not used [-Wunused-function]
static int xgene_gpio_resume(struct device *dev)
^~~~~~~~~~~~~~~~~
drivers/gpio/gpio-xgene.c:142:12: warning: 'xgene_gpio_suspend' defined but not used [-Wunused-function]
static int xgene_gpio_suspend(struct device *dev)

The warnings are harmless and can be avoided by simplifying the code and marking
the functions as __maybe_unused.

Signed-off-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/gpio-xgene.c

···
 	struct gpio_chip	chip;
 	void __iomem		*base;
 	spinlock_t		lock;
-#ifdef CONFIG_PM
 	u32			set_dr_val[XGENE_MAX_GPIO_BANKS];
-#endif
 };
 
 static int xgene_gpio_get(struct gpio_chip *gc, unsigned int offset)
···
 	return 0;
 }
 
-#ifdef CONFIG_PM
-static int xgene_gpio_suspend(struct device *dev)
+static __maybe_unused int xgene_gpio_suspend(struct device *dev)
 {
 	struct xgene_gpio *gpio = dev_get_drvdata(dev);
 	unsigned long bank_offset;
···
 	return 0;
 }
 
-static int xgene_gpio_resume(struct device *dev)
+static __maybe_unused int xgene_gpio_resume(struct device *dev)
 {
 	struct xgene_gpio *gpio = dev_get_drvdata(dev);
 	unsigned long bank_offset;
···
 }
 
 static SIMPLE_DEV_PM_OPS(xgene_gpio_pm, xgene_gpio_suspend, xgene_gpio_resume);
-#define XGENE_GPIO_PM_OPS	(&xgene_gpio_pm)
-#else
-#define XGENE_GPIO_PM_OPS	NULL
-#endif
 
 static int xgene_gpio_probe(struct platform_device *pdev)
 {
···
 		.name = "xgene-gpio",
 		.of_match_table = xgene_gpio_of_match,
 		.acpi_match_table = ACPI_PTR(xgene_gpio_acpi_match),
-		.pm     = XGENE_GPIO_PM_OPS,
+		.pm     = &xgene_gpio_pm,
 	},
 	.probe = xgene_gpio_probe,
 };