ASoC: samsung: Fix compilation error on S3C2440

ASoC: samsung: Fix compilation error on S3C2440

The commit a08485d8 ("ASoC: Samsung: Do not register samsung audio dma
device as pdev") introduced compilation error.

Combination of CONFIG_CPU_S3C2440 and CONFIG_SND_S3C24XX_I2S
caused undefined symbols 's3c_i2sv2_register_dai' and 's3c2412_i2s_dai'
in sound/soc/samsung/s3c24xx-i2s.c.

This patch fixes the problem and makes S3C2440 I2S usable again. It does
not affect S3C2412 (aka I2S-v2).

Signed-off-by: Alexey Galakhov <agalakhov@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>