ASoC: wm8580: Fix non static symbol warnings

Fixes the following sparse warnings:

sound/soc/codecs/wm8580.c:988:33: warning:
 symbol 'wm8580_data' was not declared. Should it be static?
sound/soc/codecs/wm8580.c:992:33: warning:
 symbol 'wm8581_data' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm8580.c

@@ -985,11 +985,11 @@ static const struct regmap_config wm8580_regmap = {
 	.volatile_reg = wm8580_volatile,
 };
 
-const struct wm8580_driver_data wm8580_data = {
+static const struct wm8580_driver_data wm8580_data = {
 	.num_dacs = 3,
 };
 
-const struct wm8580_driver_data wm8581_data = {
+static const struct wm8580_driver_data wm8581_data = {
 	.num_dacs = 4,
 };