ALSA: dummy: make local data static

Add missing prefix to make some local data static.

Spotted by sparse:
  sound/drivers/dummy.c:159:20: warning: symbol 'model_emu10k1' was not declared. Should it be static?
  sound/drivers/dummy.c:165:20: warning: symbol 'model_rme9652' was not declared. Should it be static?
  ....
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/drivers/dummy.c

@@ -156,13 +156,13 @@ static int emu10k1_playback_constraints(struct snd_pcm_runtime *runtime)
 	return 0;
 }
 
-struct dummy_model model_emu10k1 = {
+static struct dummy_model model_emu10k1 = {
 	.name = "emu10k1",
 	.playback_constraints = emu10k1_playback_constraints,
 	.buffer_bytes_max = 128 * 1024,
 };
 
-struct dummy_model model_rme9652 = {
+static struct dummy_model model_rme9652 = {
 	.name = "rme9652",
 	.buffer_bytes_max = 26 * 64 * 1024,
 	.formats = SNDRV_PCM_FMTBIT_S32_LE,
@@ -172,7 +172,7 @@ struct dummy_model model_rme9652 = {
 	.periods_max = 2,
 };
 
-struct dummy_model model_ice1712 = {
+static struct dummy_model model_ice1712 = {
 	.name = "ice1712",
 	.buffer_bytes_max = 256 * 1024,
 	.formats = SNDRV_PCM_FMTBIT_S32_LE,
@@ -182,7 +182,7 @@ struct dummy_model model_ice1712 = {
 	.periods_max = 1024,
 };
 
-struct dummy_model model_uda1341 = {
+static struct dummy_model model_uda1341 = {
 	.name = "uda1341",
 	.buffer_bytes_max = 16380,
 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
@@ -192,7 +192,7 @@ struct dummy_model model_uda1341 = {
 	.periods_max = 255,
 };
 
-struct dummy_model model_ac97 = {
+static struct dummy_model model_ac97 = {
 	.name = "ac97",
 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
 	.channels_min = 2,
@@ -202,7 +202,7 @@ struct dummy_model model_ac97 = {
 	.rate_max = 48000,
 };
 
-struct dummy_model model_ca0106 = {
+static struct dummy_model model_ca0106 = {
 	.name = "ca0106",
 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
 	.buffer_bytes_max = ((65536-64)*8),
@@ -216,7 +216,7 @@ struct dummy_model model_ca0106 = {
 	.rate_max = 192000,
 };
 
-struct dummy_model *dummy_models[] = {
+static struct dummy_model *dummy_models[] = {
 	&model_emu10k1,
 	&model_rme9652,
 	&model_ice1712,