ASoC: samsung: s3c2412-i2s: avoid hardcoded S3C2410_PA_IIS

The constant requires indirectly including a machine header file,
but it's not actually used any more since commit 87b132bc

 ("ASoC:
samsung: s3c24{xx,12}-i2s: port to use generic dmaengine API"), so
remove it completely.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200806182059.2431-27-krzk@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>