ASoC: wm8962: Run the headphone in class G mode when sidetone is enabled

Class W mode with sidetone is not fully supported.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/wm8962.c b/sound/soc/codecs/wm8962.c
index 245c5f8..445d209 100644
--- a/sound/soc/codecs/wm8962.c
+++ b/sound/soc/codecs/wm8962.c
@@ -2230,9 +2230,11 @@
 
 	{ "STL", "Left", "ADCL" },
 	{ "STL", "Right", "ADCR" },
+	{ "STL", NULL, "Class G" },
 
 	{ "STR", "Left", "ADCL" },
 	{ "STR", "Right", "ADCR" },
+	{ "STR", NULL, "Class G" },
 
 	{ "DACL", NULL, "SYSCLK" },
 	{ "DACL", NULL, "TOCLK" },