ASoC: fsl_asrc: Fix -Wmissing-prototypes warning

COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64

sound/soc/fsl/fsl_asrc.c:557:18: warning: no previous prototype for function 'fsl_asrc_get_dma_channel' [-Wmissing-prototypes]
struct dma_chan *fsl_asrc_get_dma_channel(struct fsl_asrc_pair *pair, bool dir)
                 ^
sound/soc/fsl/fsl_asrc.c:557:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
struct dma_chan *fsl_asrc_get_dma_channel(struct fsl_asrc_pair *pair, bool dir)
^
static

Fixes: be7bd03f ("ASoC: fsl_asrc: Move common definition to fsl_asrc_common")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: shengjiu wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1590397412-12966-1-git-send-email-shengjiu.wang@nxp.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/fsl_asrc.c

@@ -554,7 +554,8 @@ static void fsl_asrc_stop_pair(struct fsl_asrc_pair *pair)
 /**
  * Get DMA channel according to the pair and direction.
  */
-struct dma_chan *fsl_asrc_get_dma_channel(struct fsl_asrc_pair *pair, bool dir)
+static struct dma_chan *fsl_asrc_get_dma_channel(struct fsl_asrc_pair *pair,
+						 bool dir)
 {
 	struct fsl_asrc *asrc = pair->asrc;
 	enum asrc_pair_index index = pair->index;
@@ -564,7 +565,6 @@ struct dma_chan *fsl_asrc_get_dma_channel(struct fsl_asrc_pair *pair, bool dir)
 
 	return dma_request_slave_channel(&asrc->pdev->dev, name);
 }
-EXPORT_SYMBOL_GPL(fsl_asrc_get_dma_channel);
 
 static int fsl_asrc_dai_startup(struct snd_pcm_substream *substream,
 				struct snd_soc_dai *dai)