ASoC: ak5558: remove redundand includes

Remove redundant includes keeping the code as close as possible
to upstream version.

Fixes commit 6d8b9d13605c ("MLK-19118-3: ASoC: AK5558: add regulators for
ak5558")
Signed-off-by: Viorel Suman <viorel.suman@nxp.com>