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>
diff --git a/sound/soc/codecs/wm2200.c b/sound/soc/codecs/wm2200.c
index c830832..3e3f638 100644
--- a/sound/soc/codecs/wm2200.c
+++ b/sound/soc/codecs/wm2200.c
@@ -2481,7 +2481,7 @@
 }
 #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)
 };