gpio_default_irq_handler() calls callback with incorrect gpio parameter

[earlephilhower]

In the develop branch, after #850 was merged, it seems like the GPIO sent to the user callback is not correct.

I have called the init function as follows for any change on GPIO 9:

gpio_set_irq_enabled_with_callback(9 /*gpio #9*/, 12 /* rise or fall */, true /*enabled*/, _gpioInterruptDispatcher /* userland irq handler */);

When I set a breakpoint in GDB I can see that a toggle on GPIO #9 does result in a callback to the SDK gpio_default_irq_handler(), so the interrupt enables are set properly, but the callback routine gets called with 8 as the interrupting GPIO, not 9.

Right now the code is only returning GPIO 0, 8, 16, or 24:

pico-sdk/src/rp2_common/hardware_gpio/gpio.c

Lines 152 to 157 in 4c49427

	if (events && !(raw_irq_mask[core] & (1u << i))) {
	gpio_acknowledge_irq(i, events);
	if (callback) {
	callback(gpio, events);
	}
	}

Line 155 should be

         callback(i, events); 

[kilograham]

merged into develop