ASoC: wm_adsp: Mark wm_adsp2_boot_work as static

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index a061183..f6e317c 100644
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -1492,7 +1492,7 @@
 	return 0;
 }
 
-void wm_adsp2_boot_work(struct work_struct *work)
+static void wm_adsp2_boot_work(struct work_struct *work)
 {
 	struct wm_adsp *dsp = container_of(work,
 					   struct wm_adsp,