gpio: qcom_pmic: Add support for GPIO LV/MV subtype

GPIO LV (low voltage)/MV (medium voltage) subtypes have different
features and register mappings than 4CH/8CH subtypes. Add support
for LV and MV subtypes.

With GPIO LV/MV subtype available, add "qcom,pms405-gpio" compatible
which requires support for GPIO MV subtype.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>