ASoC: tlv320aic31xx: General source formatting cleanup

Simple non-functional changes including:

 * Fix spelling errors
 * Reformat code for easier reading
 * Remove unneeded code
 * Remove assignments that are always overridden
 * Normalize function return paths

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>