ASoC: fsl_spdif: Utilize the defined parameter to clear code

Utilize the defined parameter 'dev' to make the code cleaner.

Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Acked-by: Shengjiu Wang <shengjiu.wang@gmail.com>
Link: https://lore.kernel.org/r/20210128112714.16324-1-tangbin@cmss.chinamobile.com


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