ASoC: wm8994: remove wm1811_snd_controls and mixin_boost_tlv

ASoC: wm8994: remove wm1811_snd_controls and mixin_boost_tlv

Fix the following gcc warning:

sound/soc/codecs/wm8994.c:736:38: warning: ‘wm1811_snd_controls’ defined
but not used [-Wunused-const-variable=]
 static const struct snd_kcontrol_new wm1811_snd_controls[] = {
                                      ^~~~~~~~~~~~~~~~~~~

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200407082932.41511-2-yanaijie@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>