ASoC: Enable ASoC register map dump for some regmap CODECs

It's still useful to be able to poke around in the register map at
runtime.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/wm8996.c b/sound/soc/codecs/wm8996.c
index da7acae..d8da10f 100644
--- a/sound/soc/codecs/wm8996.c
+++ b/sound/soc/codecs/wm8996.c
@@ -3039,6 +3039,12 @@
 	return 0;
 }
 
+static int wm8996_soc_volatile_register(struct snd_soc_codec *codec,
+					unsigned int reg)
+{
+	return true;
+}
+
 static struct snd_soc_codec_driver soc_codec_dev_wm8996 = {
 	.probe =	wm8996_probe,
 	.remove =	wm8996_remove,
@@ -3051,6 +3057,8 @@
 	.dapm_routes = wm8996_dapm_routes,
 	.num_dapm_routes = ARRAY_SIZE(wm8996_dapm_routes),
 	.set_pll = wm8996_set_fll,
+	.reg_cache_size = WM8996_MAX_REGISTER,
+	.volatile_register = wm8996_soc_volatile_register,
 };
 
 #define WM8996_RATES (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |\