regulator: tps6586x: Convert to regulator_list_voltage_table

Also adds tps6586x_ldo0_voltages mapping table for LDO0, so we can remove the
hack in tps6586x_list_voltage() and convert it to regulator_list_voltage_table.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>