commit dcc2c012 ("ASoC: Fix gpiolib dependencies") removed a
series of unnecessary dependencies on GPIOLIB when the gpio was
optional.

A similar simplification seems valid for nau8315, so remove the
dependency as well. This will avoid the following warning

  WARNING: unmet direct dependencies detected for SND_SOC_NAU8315

   Depends on [n]: SOUND [=y] && !UML && SND [=y] && SND_SOC [=y] &&
                   GPIOLIB [=n]
   Selected by [y]:

     - SND_SOC_INTEL_SOF_NAU8825_MACH [=y] && SOUND [=y] && !UML &&
       SND [=y] && SND_SOC [=y] && SND_SOC_INTEL_MACH [=y] &&
       (SND_SOC_SOF_HDA_LINK [=y] || SND_SOC_SOF_BAYTRAIL [=n]) &&
       I2C [=y] && ACPI [=y] && SND_HDA_CODEC_HDMI [=y] &&
       SND_SOC_SOF_HDA_AUDIO_CODEC [=y] && (MFD_INTEL_LPSS [=n] ||
       COMPILE_TEST [=y])
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Ajye Huang <ajye_huang@compal.corp-partner.google.com>
Link: https://lore.kernel.org/r/20230108114351.539786-1-ajye_huang@compal.corp-partner.google.comSigned-off-by: Mark Brown <broonie@kernel.org>