ASoC: twl4030: Clean up duplicated code

Remove the open code in snd_soc_put_twl4030_opmode_enum_double() but
just call snd_soc_put_enum_double() instead, which does the very same
thing (even correctly with a lock).

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>