ASoC: tpa6130a2: Model support cleanup

Use the device name and driver_data to identify
the TPA model supported by the driver.
Board files should use either "tpa6130a2" or
"tpa6140a2" as device name to specify the model
in used on the specific board.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>