ASoC: cs42l73: Unify the way to define bits of register

Current code defines some bits with left shift to the proper bit defined in
datasheet, but some don't.
Unify the definition with proper left shift and adjust the code accordingly.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Brian Austin <brian.austin@cirrus.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>