Fix MC resets in WD

[zCoCo]

WD holding MC resets seems to do nothing. It goes through IO exp. It's possible around RC2 we made them inputs so MC could be programmed and never changed them back.

• Make resets work.
• If changes make programming MCs no longer work (i.e. if resets were inputs and they need to be inputs for MC programming), add a special MC programming build flag to WD (like the ones for Radio reset and Herc mon).