ASoC: fsl_easrc: mark PM functions __maybe_unused

ASoC: fsl_easrc: mark PM functions __maybe_unused

ifdefs are hard, and in this driver the suspend/resume functions are
the only callers of some other helpers that trigger a harmless warning
when CONFIG_PM is disabled:

sound/soc/fsl/fsl_easrc.c:1807:12: warning: 'fsl_easrc_get_firmware' defined but not used [-Wunused-function]
 1807 | static int fsl_easrc_get_firmware(struct fsl_asrc *easrc)
      |            ^~~~~~~~~~~~~~~~~~~~~~
sound/soc/fsl/fsl_easrc.c:303:12: warning: 'fsl_easrc_resampler_config' defined but not used [-Wunused-function]
  303 | static int fsl_easrc_resampler_config(struct fsl_asrc *easrc)
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~

Remove the #ifdef and just mark the callers as __maybe_unused to
suppress the warnings altogether.

Fixes: bf14c853dfac ("ASoC: fsl_easrc: Add EASRC ASoC CPU DAI drivers")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Link: https://lore.kernel.org/r/20200428212847.2926376-1-arnd@arndb.de
Signed-off-by: Mark Brown <broonie@kernel.org>