ALSA: pcmcia: constify snd_pcm_ops structures

snd_pcm_ops are not supposed to change at runtime. All functions
working with snd_pcm_ops provided by <sound/pcm.h> work with
const snd_pcm_ops. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pcmcia/pdaudiocf/pdaudiocf_pcm.c

@@ -266,7 +266,7 @@ static snd_pcm_uframes_t pdacf_pcm_capture_pointer(struct snd_pcm_substream *sub
 /*
  * operators for PCM capture
  */
-static struct snd_pcm_ops pdacf_pcm_capture_ops = {
+static const struct snd_pcm_ops pdacf_pcm_capture_ops = {
 	.open =		pdacf_pcm_capture_open,
 	.close =	pdacf_pcm_capture_close,
 	.ioctl =	snd_pcm_lib_ioctl,