ASoC: Declare soc_new_pcm() properly

Ensure that everything is seeing the same declaration by moving it to
a header file rather than putting the declaration in soc-core.c

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
diff --git a/include/sound/soc.h b/include/sound/soc.h
index 8391b0e..f75d1cc 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -317,6 +317,7 @@
 					unsigned int reg);
 int snd_soc_platform_write(struct snd_soc_platform *platform,
 					unsigned int reg, unsigned int val);
+int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num);
 
 /* Utility functions to get clock rates from various things */
 int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots);