PCAL chips ("L" seems to stand for "latched") have additional
registers starting at address 0x40 to control the latches,
interrupt mask, pull-up and pull down etc.
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>