For linear regulators, the n_voltages should be (max - min) / step + 1.

Buck voltage from 1v to 3V, per step 100mV, and vout mask is 0x1f.
If value is from 20 to 31, the voltage will all be fixed to 3V.
And LDO also, just vout range is different from 1.2v to 3v, step is the
same. If value is from 18 to 31, the voltage will also be fixed to 3v.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Reviewed-by: NChiYuan Huang <cy_huang@richtek.com>
Link: https://lore.kernel.org/r/20210627080418.1718127-1-axel.lin@ingics.comSigned-off-by: NMark Brown <broonie@kernel.org>