ASoC: sti-sas: remove unused struct members

cppcheck warnings:

sound/soc/codecs/sti-sas.c:54:25: style: struct member
'sti_dac_audio::field' is never used. [unusedStructMember]
 struct regmap_field  **field;
                        ^

sound/soc/codecs/sti-sas.c:55:24: style: struct member
'sti_dac_audio::rst' is never used. [unusedStructMember]
 struct reset_control *rst;
                       ^

sound/soc/codecs/sti-sas.c:61:25: style: struct member
'sti_spdif_audio::field' is never used. [unusedStructMember]
 struct regmap_field  **field;
                        ^
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210312182246.5153-19-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/sti-sas.c

@@ -51,14 +51,11 @@ static const struct reg_default stih407_sas_reg_defaults[] = {
 struct sti_dac_audio {
 	struct regmap *regmap;
 	struct regmap *virt_regmap;
-	struct regmap_field  **field;
-	struct reset_control *rst;
 	int mclk;
 };
 
 struct sti_spdif_audio {
 	struct regmap *regmap;
-	struct regmap_field  **field;
 	int mclk;
 };