Support interrupt-only buttons

Feature Requests
1

Hello,

I am currently porting the Niagara 821 platform to OpenWRT. As far as I can tell the only way to get notified about the reset button being pressed is through an interrupt. This sadly means that as of right now I am barred from using gpio-button-hotplug as it refuses to operate with interrupt-only buttons:

# package/kernel/gpio-button-hotplug/src/gpio-button-hotplug.c

if (button->irq) {
        dev_err(dev, "skipping button %s (only gpio buttons supported)\n",
                button->desc);
        bdata->b = &pdata->buttons[i];
        continue;
}

I can get the reset event to work by using the stock gpio_keys module, but triggerhappy does not like those events for whatever reason so I am stuck with no real solution either way.

For completeness sake, this is the DTS I wish to be supported:

  reset-button {
          compatible = "gpio-keys";
          reset {
                    label = "reset";
                    interrupts = <1>;
                    linux,code = <KEY_RESTART>;
                    debounce-interval = <60>;
          };
  };