sound: soc: codecs: mt6358: change return type of mt6358_codec_init_reg

As mt6358_codec_init_reg function always returns 0 , change return type
from int to void.

fixes below issue reported by coccicheck
sound/soc/codecs/mt6358.c:2260:5-8: Unneeded variable: "ret". Return "0"
on line 2289

Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Acked-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20190709182543.GA6611@hari-Inspiron-1545


Signed-off-by: Mark Brown <broonie@kernel.org>