ASoC: wm9712: Fix wrong value references for boolean kctl

The correct values referred by a boolean control are
value.integer.value[], not value.enumerated.item[].
The former is long while the latter is int, so it's even incompatible
on 64bit architectures.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: <stable@vger.kernel.org>