ASoC: cs35l56: Move part of cs35l56_init() to shared library

Part of the initialization code in cs35l56_init() can be re-used
by the HDA driver so move it into a new function in the shared
library.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230721132120.5523-8-rf@opensource.cirrus.com


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