ALSA: dummy: constify dummy_timer_ops structures

The dummy_timer_ops structures are never modified, so declare them as
const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/drivers/dummy.c b/sound/drivers/dummy.c
index 016e451..75b7485 100644
--- a/sound/drivers/dummy.c
+++ b/sound/drivers/dummy.c
@@ -351,7 +351,7 @@
 	kfree(substream->runtime->private_data);
 }
 
-static struct dummy_timer_ops dummy_systimer_ops = {
+static const struct dummy_timer_ops dummy_systimer_ops = {
 	.create =	dummy_systimer_create,
 	.free =		dummy_systimer_free,
 	.prepare =	dummy_systimer_prepare,
@@ -475,7 +475,7 @@
 	kfree(dpcm);
 }
 
-static struct dummy_timer_ops dummy_hrtimer_ops = {
+static const struct dummy_timer_ops dummy_hrtimer_ops = {
 	.create =	dummy_hrtimer_create,
 	.free =		dummy_hrtimer_free,
 	.prepare =	dummy_hrtimer_prepare,