ASoC: cs42l42: Split I2C identity into separate module

Split the I2C bus driver definition and probe()/remove() into a
separate module so that a SoundWire build of CS42L42 support does
not have a spurious dependency on I2C.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20220915094444.11434-8-povik+lin@cutebit.org


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