sound: oss/vwsnd: Add missing inclusion of linux/delay.h

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/oss/vwsnd.c b/sound/oss/vwsnd.c
index 7e814a5..d8db9023 100644
--- a/sound/oss/vwsnd.c
+++ b/sound/oss/vwsnd.c
@@ -149,6 +149,7 @@
 #include <linux/interrupt.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 
 #include <asm/visws/cobalt.h>