ASoC: cs35l45: Add AMP Enable Switch control

The "AMP Enable Switch" is useful in systems with multiple
amplifiers connected to the same audio bus
but not all of them are needed for all use cases.
Signed-off-by: Vlad Karpovich <vkarpovi@opensource.cirrus.com>
Acked-by: Ricardo Rivera-Matos <rriveram@opensource.cirrus.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230831162042.471801-4-vkarpovi@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/cs35l45.c

@@ -417,6 +417,8 @@ static const struct snd_kcontrol_new cs35l45_dsp_muxes[] = {
 static const struct snd_kcontrol_new cs35l45_dac_muxes[] = {
 	SOC_DAPM_ENUM("DACPCM Source", cs35l45_dacpcm_enums[0]),
 };
+static const struct snd_kcontrol_new amp_en_ctl =
+	SOC_DAPM_SINGLE("Switch", SND_SOC_NOPM, 0, 1, 0);
 
 static const struct snd_soc_dapm_widget cs35l45_dapm_widgets[] = {
 	SND_SOC_DAPM_SPK("DSP1 Preload", NULL),
@@ -479,6 +481,8 @@ static const struct snd_soc_dapm_widget cs35l45_dapm_widgets[] = {
 
 	SND_SOC_DAPM_MUX("DACPCM Source", SND_SOC_NOPM, 0, 0, &cs35l45_dac_muxes[0]),
 
+	SND_SOC_DAPM_SWITCH("AMP Enable", SND_SOC_NOPM, 0, 0, &amp_en_ctl),
+
 	SND_SOC_DAPM_OUT_DRV("AMP", SND_SOC_NOPM, 0, 0, NULL, 0),
 
 	SND_SOC_DAPM_OUTPUT("SPK"),
@@ -586,7 +590,8 @@ static const struct snd_soc_dapm_route cs35l45_dapm_routes[] = {
 
 	CS35L45_DAC_MUX_ROUTE("DACPCM"),
 
-	{ "SPK", NULL, "AMP"},
+	{ "AMP Enable", "Switch", "AMP" },
+	{ "SPK", NULL, "AMP Enable"},
 };
 
 static const char * const amplifier_mode_texts[] = {"SPK", "RCV"};