regulator: axp20x: Fix axp22x ldo_io voltage ranges

The minium voltage of 1800mV is a copy and paste error from the axp20x
regulator info. The correct minimum voltage for the ldo_io regulators
on the axp22x is 700mV.

Fixes: 1b82b4e4 ("regulator: axp20x: Add support for AXP22X regulators")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Mark Brown <broonie@kernel.org>