ASoC: AMD: Fix Kconfig warning without GPIOLIB

While do rand build without GPIOLIB, we get Kconfig warning:\

WARNING: unmet direct dependencies detected for SND_SOC_MAX98357A
  Depends on [n]: SOUND [=y] && !UML && SND [=m] && SND_SOC [=m] && GPIOLIB [=n]
  Selected by [m]:
  - SND_SOC_AMD_CZ_DA7219MX98357_MACH [=m] && SOUND [=y] && !UML && SND [=m] && SND_SOC [=m] && SND_SOC_AMD_ACP [=m] && I2C [=y]

Add GPIOLIB dependency to fix this.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20190822143007.73644-1-yuehaibing@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>