hwrng: imx-rngc - simplify the power management definitions

Use the SIMPLE_DEV_PM_OPS() macro instead of populating a struct
dev_pm_ops directly. The suspend and resume functions will now be used
for both hibernation and suspend to ram.

If power management is disabled, SIMPLE_DEV_PM_OPS() evaluates to
nothing, The two functions won't be used and won't be included in the
kernel. Mark them as __maybe_unused to clarify that this is intended
behaviour.

With these modifications in place, we don't need the #ifdefs for power
management any more.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/imx-rngc.c

@@ -282,8 +282,7 @@ static int __exit imx_rngc_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM
-static int imx_rngc_suspend(struct device *dev)
+static int __maybe_unused imx_rngc_suspend(struct device *dev)
 {
 	struct imx_rngc *rngc = dev_get_drvdata(dev);
 
@@ -292,7 +291,7 @@ static int imx_rngc_suspend(struct device *dev)
 	return 0;
 }
 
-static int imx_rngc_resume(struct device *dev)
+static int __maybe_unused imx_rngc_resume(struct device *dev)
 {
 	struct imx_rngc *rngc = dev_get_drvdata(dev);
 
@@ -301,11 +300,7 @@ static int imx_rngc_resume(struct device *dev)
 	return 0;
 }
 
-static const struct dev_pm_ops imx_rngc_pm_ops = {
-	.suspend	= imx_rngc_suspend,
-	.resume		= imx_rngc_resume,
-};
-#endif
+SIMPLE_DEV_PM_OPS(imx_rngc_pm_ops, imx_rngc_suspend, imx_rngc_resume);
 
 static const struct of_device_id imx_rngc_dt_ids[] = {
 	{ .compatible = "fsl,imx25-rngb", .data = NULL, },
@@ -316,9 +311,7 @@ MODULE_DEVICE_TABLE(of, imx_rngc_dt_ids);
 static struct platform_driver imx_rngc_driver = {
 	.driver = {
 		.name = "imx_rngc",
-#ifdef CONFIG_PM
 		.pm = &imx_rngc_pm_ops,
-#endif
 		.of_match_table = imx_rngc_dt_ids,
 	},
 	.remove = __exit_p(imx_rngc_remove),