ASoC: io: Use dev_get_regmap() if driver doesn't provide a regmap

Less error prone and one less line of code in drivers.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>

sound/soc/soc-io.c

@@ -142,6 +142,8 @@ int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
 	case SND_SOC_REGMAP:
 		/* Device has made its own regmap arrangements */
 		codec->using_regmap = true;
+		if (!codec->control_data)
+			codec->control_data = dev_get_regmap(codec->dev, NULL);
 
 		ret = regmap_get_val_bytes(codec->control_data);
 		/* Errors are legitimate for non-integer byte multiples */