ASoC: Prototype s3c64xx_i2s_get_clock()

So machine drivers can see the declaration.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Jassi Brar <jassi.brar@samsung.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

sound/soc/s3c24xx/s3c64xx-i2s.h

@@ -36,5 +36,6 @@ struct clk;
 	(SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE |\
 	 SNDRV_PCM_FMTBIT_S24_LE)
 
+struct clk *s3c64xx_i2s_get_clock(struct snd_soc_dai *dai);
 
 #endif /* __SND_SOC_S3C24XX_S3C64XX_I2S_H */