ASoC: cs4271: add regulator consumer support

The cs4271 has three power domains: vd, vl and va.
Enable them all, as long as the codec is in use.

While at it, factored out the reset code into its own function.

Signed-off-by: Pascal Huerst <pascal.huerst@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>