[DRIVER][TLV320] fix "Mixer Amp. Driver Gain Volume" dapm control

The "Mixer Amp. Driver Gain Volume" control, which controls registers
AIC32X4_MALVOL and AIC32X4_MARVOL, is registered with a sign bit (bit 5).
This makes the control freeze in alsamixer when set to a value >= 0x20
(0b100000), because values 0x20-0x28 are wrongly considered negative.
This patch removes the sign bit configuration.

sound/soc/codecs/tlv320aic32x4.c

@@ -291,8 +291,8 @@ static const struct snd_kcontrol_new aic32x4_snd_controls[] = {
 	SOC_ENUM("LO Playback Common Mode Switch", lo_cm_enum),
 	SOC_DOUBLE_R("Mic PGA Switch", AIC32X4_LMICPGAVOL,
 			AIC32X4_RMICPGAVOL, 7, 0x01, 1),
-	SOC_DOUBLE_R_S_TLV("Mixer Amp. Driver Gain Volume", AIC32X4_MALVOL,
-			AIC32X4_MARVOL, 0, -0x0, 0x28, 5, 1, tlv_ma_vol),
+	SOC_DOUBLE_R_TLV("Mixer Amp. Driver Gain Volume", AIC32X4_MALVOL,
+			AIC32X4_MARVOL, 0, 0x28, 1, tlv_ma_vol),
 
 	SOC_SINGLE("ADCFGA Left Mute Switch", AIC32X4_ADCFGA, 7, 1, 0),
 	SOC_SINGLE("ADCFGA Right Mute Switch", AIC32X4_ADCFGA, 3, 1, 0),