ASoC: wm8990: Remove incorrect comments

Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm8990.c

@@ -47,10 +47,6 @@ static int wm8990_volatile_register(struct snd_soc_codec *codec,
 	}
 }
 
-/*
- * wm8990 register cache.  Note that register 0 is not included in the
- * cache.
- */
 static const u16 wm8990_reg[] = {
 	0x8990,     /* R0  - Reset */
 	0x0000,     /* R1  - Power Management (1) */