ASoC: Intel: kbl_da7219_max98357a: remove unused variable 'constraints_16000' and 'ch_mono'

sound/soc/intel/boards/kbl_da7219_max98357a.c:343:48:
 warning: constraints_16000 defined but not used [-Wunused-const-variable=]
sound/soc/intel/boards/kbl_da7219_max98357a.c:348:27:
 warning: ch_mono defined but not used [-Wunused-const-variable=]

They are never used, so can be removed.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20191224140237.36732-1-yuehaibing@huawei.com


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