DWC/firmware mismatch

[jumpedwithbothfeet]

@Phaedrux all sorted it was a cheap usb cable! Thanks again for your help

[Phaedrux]

I've added some notes to the Duet3 documentation on powering the SBC. When in doubt, power it separately.

https://duet3d.dozuki.com/Wiki/Duet_3_Mainboard_6HC_Hardware_Overview?revisionid=HEAD#Section_Electronics_power_consumption