ASoC: mediatek: mt8183: make some functions static

Fixes the following sparse warnings:

sound/soc/mediatek/mt8183/mt8183-dai-i2s.c:966:5: warning:
 symbol 'mt8183_dai_i2s_get_share' was not declared. Should it be static?
sound/soc/mediatek/mt8183/mt8183-dai-i2s.c:986:5: warning:
 symbol 'mt8183_dai_i2s_set_priv' was not declared. Should it be static?

Fixes: a94aec03 ("ASoC: mediatek: mt8183: add platform driver")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/mediatek/mt8183/mt8183-dai-i2s.c

@@ -963,7 +963,7 @@ static const struct mtk_afe_i2s_priv mt8183_i2s_priv[DAI_I2S_NUM] = {
 	},
 };
 
-int mt8183_dai_i2s_get_share(struct mtk_base_afe *afe)
+static int mt8183_dai_i2s_get_share(struct mtk_base_afe *afe)
 {
 	struct mt8183_afe_private *afe_priv = afe->platform_priv;
 	const struct device_node *of_node = afe->dev->of_node;
@@ -983,7 +983,7 @@ int mt8183_dai_i2s_get_share(struct mtk_base_afe *afe)
 	return 0;
 }
 
-int mt8183_dai_i2s_set_priv(struct mtk_base_afe *afe)
+static int mt8183_dai_i2s_set_priv(struct mtk_base_afe *afe)
 {
 	struct mt8183_afe_private *afe_priv = afe->platform_priv;
 	struct mtk_afe_i2s_priv *i2s_priv;