Fix the following gcc warning:

sound/soc/intel/common/soc-acpi-intel-icl-match.c:90:45: warning:
‘rt1308_2_adr’ defined but not used [-Wunused-const-variable=]
 static const struct snd_soc_acpi_adr_device rt1308_2_adr[] = {
                                             ^~~~~~~~~~~~
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200410081117.21319-1-yanaijie@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>