gpio: max77620: Initialize hardware state of interrupts

I noticed on Nexus 7 that after rebooting from downstream kernel to
upstream, the GPIO interrupt is triggering non-stop despite interrupts
being disabled for all of GPIOs. This happens because Nexus 7 uses a
soft-reboot, meaning that bootloader should take care of resetting
hardware, but the bootloader doesn't do it well. As a result, GPIO
interrupt may be left ON at a boot time. Let's mask all GPIO interrupts
at the driver's initialization time in order to resolve the issue.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Link: https://lore.kernel.org/r/20200709171203.12950-7-digetx@gmail.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>