regulator: sy7636a: Make regulator_desc static const

It's only used in this file and never changed, make it static const.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Alistair Francis <alistair@alistair23.me>
Link: https://lore.kernel.org/r/20210616034458.3499522-2-axel.lin@ingics.com


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