regulator: as3722: Don't set min_uV/uV_step/linear_min_sel for linear_ranges

These settings are not used when using linear_ranges and it makes the code
looks confusing. Thus remove them.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>