ASoc: tas2770: Remove unused defines and variables

Remove unused defines and structure variables that are not
referenced by the code.  If these are needed for future
enhancements then they should be added at that time.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20191007171157.17813-3-dmurphy@ti.com


Signed-off-by: Mark Brown <broonie@kernel.org>