ASoC: mediatek: mt8365: remove unused mt8365_i2s_hd_str

The mt8365_i2s_enum and mt8365_i2s_hd_str variables are not
used anywhere, but cause a warning when building with C=1
or when enabling -Wunused-const-variable:

sound/soc/mediatek/mt8365/mt8365-dai-i2s.c:781:27: error: 'mt8365_i2s_hd_str' defined but not used [-Werror=unused-const-variable=]
  781 | static const char * const mt8365_i2s_hd_str[] = {
      |                           ^~~~~~~~~~~~~~~~~

Remove these for the moment, they can be added back if a
user comes up.

Fixes: 402bbb1 ("ASoC: mediatek: mt8365: Add I2S DAI support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://patch.msgid.link/20240907200053.3027553-1-arnd@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: arndb

sound/soc/mediatek/mt8365/mt8365-dai-i2s.c

@@ -777,13 +777,6 @@ static struct snd_soc_dai_driver mtk_dai_i2s_driver[] = {
 	}
 };
 
-/* low jitter control */
-static const char * const mt8365_i2s_hd_str[] = {
-	"Normal", "Low_Jitter"
-};
-
-static SOC_ENUM_SINGLE_EXT_DECL(mt8365_i2s_enum, mt8365_i2s_hd_str);
-
 static const char * const fmi2sin_text[] = {
 	"OPEN", "FM_2ND_I2S_IN"
 };