staging: regulator: hi6421v600-regulator: cleanup DT settings

staging: regulator: hi6421v600-regulator: cleanup DT settings

Currently, an array is used to store both vsel and enable
settings, mixing registers, masks and bit settings.

Change it in order to have one separate property for each.

This makes easier to understand the contents of the DT
file, and to describe it at the Documentation/.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/fd72215b0a7da55dd727c2d7bd01c047a46cdd2e.1597647359.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>