regulator: bd718x7, bd71828, Fix dvs voltage levels

The ROHM BD718x7 and BD71828 drivers support setting HW state
specific voltages from device-tree. This is used also by various
in-tree DTS files.

These drivers do incorrectly try to compose bit-map using enum
values. By a chance this works for first two valid levels having
values 1 and 2 - but setting values for the rest of the levels
do indicate capability of setting values for first levels as
well. Luckily the regulators which support setting values for
SUSPEND/LPSR do usually also support setting values for RUN
and IDLE too - thus this has not been such a fatal issue.

Fix this by defining the old enum values as bits and fixing the
parsing code. This allows keeping existing IC specific drivers
intact and only slightly changing the rohm-regulator.c

Fixes: 21b72156

 ("regulator: bd718x7: Split driver to common and bd718x7 specific parts")
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20210212080023.GA880728@localhost.localdomain
Signed-off-by: Mark Brown <broonie@kernel.org>