- Remove the old, not-expressive-enough interrupt flags, and replace them
with a new set of interrupt-specific flags that can express a wide
variety of interrupt configurations (pos, neg, and double-edge, high
and low level).
- Remove old, unused gpio_pin_ctl_intr() and gpio_pin_irqen(), and
replace them with gpio_intr_establish(), gpio_intr_disestablish(),
and gpio_intr_str(). Corresponding fields in the gpio_chipset_tag
are also added for back-end controllers, which now handle the actual
dispatch of GPIO interrupts in order to properly support level-triggered
interrupts as well as interoperate properly with FDT-registered
interrupts.
Piggy-back on the 8.99.18 version bump.
Inspired by initial work from Brad Spencer.
PR kern/51676
b936dffb43