hwrng: exynos - use __maybe_unused to hide pm functions

The exynos random driver uses #ifdef to check for CONFIG_PM, but
then uses SIMPLE_DEV_PM_OPS, which leaves the references out when
CONFIG_PM_SLEEP is not defined, so we get a warning with
PM=y && PM_SLEEP=n:

drivers/char/hw_random/exynos-rng.c:166:12: error: 'exynos_rng_suspend' defined but not used [-Werror=unused-function]
drivers/char/hw_random/exynos-rng.c:171:12: error: 'exynos_rng_resume' defined but not used [-Werror=unused-function]

This removes the incorrect #ifdef and instead uses a __maybe_unused
annotation to let the compiler know it can silently drop
the function definition.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/exynos-rng.c

@@ -144,8 +144,7 @@ static int exynos_rng_probe(struct platform_device *pdev)
 	return devm_hwrng_register(&pdev->dev, &exynos_rng->rng);
 }
 
-#ifdef CONFIG_PM
-static int exynos_rng_runtime_suspend(struct device *dev)
+static int __maybe_unused exynos_rng_runtime_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct exynos_rng *exynos_rng = platform_get_drvdata(pdev);
@@ -155,7 +154,7 @@ static int exynos_rng_runtime_suspend(struct device *dev)
 	return 0;
 }
 
-static int exynos_rng_runtime_resume(struct device *dev)
+static int __maybe_unused exynos_rng_runtime_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct exynos_rng *exynos_rng = platform_get_drvdata(pdev);
@@ -163,12 +162,12 @@ static int exynos_rng_runtime_resume(struct device *dev)
 	return clk_prepare_enable(exynos_rng->clk);
 }
 
-static int exynos_rng_suspend(struct device *dev)
+static int __maybe_unused exynos_rng_suspend(struct device *dev)
 {
 	return pm_runtime_force_suspend(dev);
 }
 
-static int exynos_rng_resume(struct device *dev)
+static int __maybe_unused exynos_rng_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct exynos_rng *exynos_rng = platform_get_drvdata(pdev);
@@ -180,7 +179,6 @@ static int exynos_rng_resume(struct device *dev)
 
 	return exynos_rng_configure(exynos_rng);
 }
-#endif
 
 static const struct dev_pm_ops exynos_rng_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(exynos_rng_suspend, exynos_rng_resume)