ASoC: soc_codec_reg_show use snd_soc_codec_readable_register

Use snd_soc_codec_readable_register instead of open-coding it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/soc-core.c

@@ -143,7 +143,7 @@ static ssize_t soc_codec_reg_show(struct snd_soc_codec *codec, char *buf,
 		step = codec->driver->reg_cache_step;
 
 	for (i = 0; i < codec->driver->reg_cache_size; i += step) {
-		if (codec->readable_register && !codec->readable_register(codec, i))
+		if (!snd_soc_codec_readable_register(codec, i))
 			continue;
 		if (codec->driver->display_register) {
 			count += codec->driver->display_register(codec, buf + count,