mfd: exynos-lpass: Mark PM functions as __maybe_unused

The newly added exynos lpass driver produces a build warning when
CONFIG_PM is disabled since the only callers of exynos_lpass_disable
are under an #ifdef:

drivers/mfd/exynos-lpass.c:93:13: error: 'exynos_lpass_disable' defined but not used [-Werror=unused-function]
static void exynos_lpass_disable(struct exynos_lpass *lpass)

This removes the #ifdef and replaces it with __maybe_unused annotations
so the compiler can leave out the unused code silently with less
room for mistakes.

Fixes: 36c26760bba8 ("mfd: Add Samsung Exynos Low Power Audio Subsystem driver")
Signed-off-by: Arnd Bergmann <[e-mail]>
Reviewed-by: Sylwester Nawrocki <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/exynos-lpass.c

···
 	return of_platform_populate(dev->of_node, NULL, NULL, dev);
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int exynos_lpass_suspend(struct device *dev)
+static int __maybe_unused exynos_lpass_suspend(struct device *dev)
 {
 	struct exynos_lpass *lpass = dev_get_drvdata(dev);
 
···
 	return 0;
 }
 
-static int exynos_lpass_resume(struct device *dev)
+static int __maybe_unused exynos_lpass_resume(struct device *dev)
 {
 	struct exynos_lpass *lpass = dev_get_drvdata(dev);
 
···
 
 	return 0;
 }
-#endif
 
 static SIMPLE_DEV_PM_OPS(lpass_pm_ops, exynos_lpass_suspend,
 					exynos_lpass_resume);