ASoC: es8328: remove unused variable 'pga_tlv'

sound/soc/codecs/es8328.c:102:35: warning:
 pga_tlv defined but not used [-Wunused-const-variable=]

They are never used, so can be removed.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20190815092056.28724-1-yuehaibing@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/es8328.c

@@ -99,7 +99,6 @@ static SOC_ENUM_SINGLE_DECL(adcpol,
 
 static const DECLARE_TLV_DB_SCALE(play_tlv, -3000, 100, 0);
 static const DECLARE_TLV_DB_SCALE(dac_adc_tlv, -9600, 50, 0);
-static const DECLARE_TLV_DB_SCALE(pga_tlv, 0, 300, 0);
 static const DECLARE_TLV_DB_SCALE(bypass_tlv, -1500, 300, 0);
 static const DECLARE_TLV_DB_SCALE(mic_tlv, 0, 300, 0);