ASoC: Constify dev_pm_ops variables

The dev_pm_ops variables are not modified after initialization in these
drivers, so make them const.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm2200.c

@@ -2481,7 +2481,7 @@ static int wm2200_runtime_resume(struct device *dev)
 }
 #endif
 
-static struct dev_pm_ops wm2200_pm = {
+static const struct dev_pm_ops wm2200_pm = {
 	SET_RUNTIME_PM_OPS(wm2200_runtime_suspend, wm2200_runtime_resume,
 			   NULL)
 };

sound/soc/codecs/wm5100.c

@@ -2708,7 +2708,7 @@ static int wm5100_runtime_resume(struct device *dev)
 }
 #endif
 
-static struct dev_pm_ops wm5100_pm = {
+static const struct dev_pm_ops wm5100_pm = {
 	SET_RUNTIME_PM_OPS(wm5100_runtime_suspend, wm5100_runtime_resume,
 			   NULL)
 };

sound/soc/codecs/wm8962.c

@@ -3859,7 +3859,7 @@ static int wm8962_runtime_suspend(struct device *dev)
 }
 #endif
 
-static struct dev_pm_ops wm8962_pm = {
+static const struct dev_pm_ops wm8962_pm = {
 	SET_RUNTIME_PM_OPS(wm8962_runtime_suspend, wm8962_runtime_resume, NULL)
 };