On SoundWire the system resume cannot restore registers until the
host controller has re-enumerated the peripheral.

This patch splits cs42l42_resume() into two functions, one to
power up and the other to restore registers, ready for adding
SoundWire support.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20220915094444.11434-6-povik+lin@cutebit.orgSigned-off-by: Mark Brown <broonie@kernel.org>