ASoC: fix 0-day warnings with snd_soc_new_compress()

All conditionally-defined routines in include/sound/soc.h expose a
static inline fallback to avoid 0-day warnings and compilation issues,
except snd_soc_new_compress().

Fixes: 5db6aab6 ('ASoC: topology: Add support for compressed PCMs')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>