gpio: cadence: Add support for edge-triggered interrupts

gpio: cadence: Add support for edge-triggered interrupts

The Cadence GPIO controller (CDNS IP6508) supports edge-triggered
interrupts (rising, falling, and both) via IRQ_TYPE, IRQ_VALUE,
and IRQ_ANY_EDGE registers. This commit enables support for these
modes in cdns_gpio_irq_set_type().

Although the interrupt status register is cleared on read and lacks
per-pin acknowledgment, the driver already handles this safely by
reading the ISR once and dispatching all pending interrupts immediately.
This allows edge IRQs to be used reliably in controlled environments.

Signed-off-by: Tzu-Hao Wei <twei@axiado.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Swark Yang <syang@axiado.com>
Link: https://lore.kernel.org/r/20260109-axiado-ax3000-cadence-gpio-support-v2-2-fc1e28edf68a@axiado.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>