ALSA : pcsp: pcsp_lib: constify snd_pcsp_playback_ops

File size before:
   text	   data	    bss	    dec	    hex	filename
   2027	    168	      1	   2196	    894	sound/drivers/pcsp/pcsp_lib.o

File size After:
   text	   data	    bss	    dec	    hex	filename
   2155	     40	      1	   2196	    894	sound/drivers/pcsp/pcsp_lib.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/drivers/pcsp/pcsp_lib.c

@@ -323,7 +323,7 @@ static int snd_pcsp_playback_open(struct snd_pcm_substream *substream)
 	return 0;
 }
 
-static struct snd_pcm_ops snd_pcsp_playback_ops = {
+static const struct snd_pcm_ops snd_pcsp_playback_ops = {
 	.open = snd_pcsp_playback_open,
 	.close = snd_pcsp_playback_close,
 	.ioctl = snd_pcm_lib_ioctl,