ASoC: wm8904: fix wrong outputs volume after power reactivation

Restore volume after charge pump and PGA activation to ensure
that volume settings are correctly applied when re-enabling codec
from SND_SOC_BIAS_OFF state.
CLASS_W, CHARGE_PUMP and POWER_MANAGEMENT_2 register configuration
affect how the volume register are applied and must be configured first.

Fixes: a91eb199e4dc ("ASoC: Initial WM8904 CODEC driver")
Link: https://lore.kernel.org/all/[e-mail]/
Signed-off-by: Emanuele Ghidoli <[e-mail]>
Signed-off-by: Francesco Dolcini <[e-mail]>
Acked-by: Charles Keepax <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/codecs/wm8904.c

···
 	int dcs_mask;
 	int dcs_l, dcs_r;
 	int dcs_l_reg, dcs_r_reg;
+	int an_out_reg;
 	int timeout;
 	int pwr_reg;
 
···
 		dcs_mask = WM8904_DCS_ENA_CHAN_0 | WM8904_DCS_ENA_CHAN_1;
 		dcs_r_reg = WM8904_DC_SERVO_8;
 		dcs_l_reg = WM8904_DC_SERVO_9;
+		an_out_reg = WM8904_ANALOGUE_OUT1_LEFT;
 		dcs_l = 0;
 		dcs_r = 1;
 		break;
···
 		dcs_mask = WM8904_DCS_ENA_CHAN_2 | WM8904_DCS_ENA_CHAN_3;
 		dcs_r_reg = WM8904_DC_SERVO_6;
 		dcs_l_reg = WM8904_DC_SERVO_7;
+		an_out_reg = WM8904_ANALOGUE_OUT2_LEFT;
 		dcs_l = 2;
 		dcs_r = 3;
 		break;
···
 		snd_soc_component_update_bits(component, reg,
 				    WM8904_HPL_ENA_OUTP | WM8904_HPR_ENA_OUTP,
 				    WM8904_HPL_ENA_OUTP | WM8904_HPR_ENA_OUTP);
+
+		/* Update volume, requires PGA to be powered */
+		val = snd_soc_component_read(component, an_out_reg);
+		snd_soc_component_write(component, an_out_reg, val);
 		break;
 
 	case SND_SOC_DAPM_POST_PMU: