ASoC: lochnagar: Fix unused lochnagar_of_match warning

lochnagar_of_match is used unconditionally, so COMPILE_TEST builds
without OF warn:

  sound/soc/codecs/lochnagar-sc.c:247:34: error: ‘lochnagar_of_match’ defined but not used [-Werror=unused-const-variable=]

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221215134337.77944-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Mark Brown <broonie@kernel.org>