Revert "ASoC: tpa6130a2: Support for limiting gain"

This reverts commit 6f3991152f.

Since core has now support for limiting the volume on controls this
patch is not needed.  Furthermore, this patch actually prevents the core
to set new volume on the TPA.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/sound/tpa6130a2-plat.h

@@ -31,7 +31,6 @@ enum tpa_model {
 struct tpa6130a2_platform_data {
 	enum tpa_model id;
 	int power_gpio;
-	int limit_gain;
 };
 
 #endif