ASoC: Disable thermal shutdown when not using speakers in wm_hubs

The thermal shutdown support in wm_hubs devices is tied to the speaker
drivers (which are the only high power subsystems within the device).
Ensure minimal current usage when the thermal shutdown support is not
required by disabling the circuit when the speaker drivers are powered
down.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm_hubs.c

@@ -654,6 +654,7 @@ SND_SOC_DAPM_MIXER("SPKL Boost", SND_SOC_NOPM, 0, 0,
 SND_SOC_DAPM_MIXER("SPKR Boost", SND_SOC_NOPM, 0, 0,
 		   right_speaker_boost, ARRAY_SIZE(right_speaker_boost)),
 
+SND_SOC_DAPM_SUPPLY("TSHUT", WM8993_POWER_MANAGEMENT_2, 14, 0, NULL, 0),
 SND_SOC_DAPM_PGA("SPKL Driver", WM8993_POWER_MANAGEMENT_1, 12, 0,
 		 NULL, 0),
 SND_SOC_DAPM_PGA("SPKR Driver", WM8993_POWER_MANAGEMENT_1, 13, 0,
@@ -789,10 +790,12 @@ static const struct snd_soc_dapm_route analogue_routes[] = {
 	{ "SPKL Driver", NULL, "VMID" },
 	{ "SPKL Driver", NULL, "SPKL Boost" },
 	{ "SPKL Driver", NULL, "CLK_SYS" },
+	{ "SPKL Driver", NULL, "TSHUT" },
 
 	{ "SPKR Driver", NULL, "VMID" },
 	{ "SPKR Driver", NULL, "SPKR Boost" },
 	{ "SPKR Driver", NULL, "CLK_SYS" },
+	{ "SPKR Driver", NULL, "TSHUT" },
 
 	{ "SPKOUTLP", NULL, "SPKL Driver" },
 	{ "SPKOUTLN", NULL, "SPKL Driver" },