soc: fsl_asrc: Make some functions static

Fix the following warning:

sound/soc/fsl/fsl_asrc.c:157:5: warning:
symbol 'fsl_asrc_request_pair' was not declared. Should it be static?
sound/soc/fsl/fsl_asrc.c:200:6: warning:
symbol 'fsl_asrc_release_pair' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: ChenTao <chentao107@huawei.com>
Link: https://lore.kernel.org/r/20200507022959.183739-1-chentao107@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/fsl_asrc.c

@@ -154,7 +154,7 @@ static void fsl_asrc_sel_proc(int inrate, int outrate,
  * within range [ANCA, ANCA+ANCB-1], depends on the channels of pair A
  * while pair A and pair C are comparatively independent.
  */
-int fsl_asrc_request_pair(int channels, struct fsl_asrc_pair *pair)
+static int fsl_asrc_request_pair(int channels, struct fsl_asrc_pair *pair)
 {
 	enum asrc_pair_index index = ASRC_INVALID_PAIR;
 	struct fsl_asrc *asrc = pair->asrc;
@@ -197,7 +197,7 @@ int fsl_asrc_request_pair(int channels, struct fsl_asrc_pair *pair)
  *
  * It clears the resource from asrc and releases the occupied channels.
  */
-void fsl_asrc_release_pair(struct fsl_asrc_pair *pair)
+static void fsl_asrc_release_pair(struct fsl_asrc_pair *pair)
 {
 	struct fsl_asrc *asrc = pair->asrc;
 	enum asrc_pair_index index = pair->index;