ASoC: twl6040: Add control for HS and HF mono to stereo selection

The new controls will give user the ability to route the left PDM channel
data to the right headset/handsfree DAC.
HS mono to stereo switch: PDM channel 1 (or mono) data to both HS DAC.
HF mono to stereo switch: PDM channel 3 data to both HF DAC.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/twl6040.c

@@ -606,6 +606,14 @@ static const struct snd_kcontrol_new twl6040_snd_controls[] = {
 		twl6040_headset_power_get_enum,
 		twl6040_headset_power_put_enum),
 
+	/* Left HS PDM data routed to Right HSDAC */
+	SOC_SINGLE("Headset Mono to Stereo Playback Switch",
+		TWL6040_REG_HSRCTL, 7, 1, 0),
+
+	/* Left HF PDM data routed to Right HFDAC */
+	SOC_SINGLE("Handsfree Mono to Stereo Playback Switch",
+		TWL6040_REG_HFRCTL, 5, 1, 0),
+
 	SOC_ENUM_EXT("PLL Selection", twl6040_power_mode_enum,
 		twl6040_pll_get_enum, twl6040_pll_put_enum),
 };