ASoC: max98088: Fix logging of hardware revision.

The hardware revision of the codec is based at 0x40.  Subtract that
before convering to ASCII.  The same as it is done for 98095.
Signed-off-by: Dylan Reid <dgreid@chromium.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org

sound/soc/codecs/max98088.c

@@ -2024,7 +2024,7 @@ static int max98088_probe(struct snd_soc_codec *codec)
                        ret);
                goto err_access;
        }
-       dev_info(codec->dev, "revision %c\n", ret + 'A');
+       dev_info(codec->dev, "revision %c\n", ret - 0x40 + 'A');
 
        snd_soc_write(codec, M98088_REG_51_PWR_SYS, M98088_PWRSV);