When not all SW pins are used, it's useful to disable those that aren't.
Can reduce audible noise.
```
Layout:
D7:D4 D3 D2:D1 D0
SWD LGC OSDE SSD
SWS: SWx Setting. Change how many SW pins are active
LGC: H/L Logic
SSD: Software Shutdown Control
```
Signed-off-by: Daniel Schaefer <dhs@frame.work>
367b8e09d9