IRQ input pin needs a glitch filter

[RTimothyEdwards]

Needed for MPW-three: Put a glitch filter between the IRQ pin and the management core, using for example the glitch filter circuit used on the xres4v2 I/O pad, or else implement a simple digital glitch filter within the management SoC. This would allow the IRQ pin to be connected directly to a button.

However, there is hysteresis built into the GPIOv2 I/O pad, so the existing system (striVe or caravel MPW-one) should be tested to see if maybe it's not an issue in practice.