gpio: rockchip: Reset int_bothedge when changing trigger

With v2 hardware, an IRQ can be configured to trigger on both edges via
a bit in the int_bothedge register. Currently, the driver sets this bit
when changing the trigger type to IRQ_TYPE_EDGE_BOTH, but fails to reset
this bit if the trigger type is later changed to something else. This
causes spurious IRQs, and when using gpio-keys with wakeup-event-action
set to EV_ACT_(DE)ASSERTED, those IRQs translate into spurious wakeups.

Fixes: 3bcbd1a8 ("gpio/rockchip: support next version gpio controller")
Reported-by: Guillaume Savaton <guillaume@baierouge.fr>
Tested-by: Guillaume Savaton <guillaume@baierouge.fr>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>