gpio: max77620: Configure interrupt trigger level

The GPIO sub modules of MAX77620 offers to configure the GPIO
interrupt trigger level as RISING and FALLING edge.

Pass this information to regmap-irg when registering for GPIO
interrupts.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>