There are two Wittons in Norfolk, one is near Norwich and the other is near to North Walsham. This is what The Concise Oxford Dictionary Of English Placenames has to say about the Witton near to North Walsham.
Witton, Norfolk. Widituna in Domesday Book, Wottone in 1254. Old English Widutun, a place near a wood.
There are a few reasons as to the evolution of the place-name Witton, but most are simply a place near a wood, which explains why this is a relatively common name for a settlement. This is though different to Watton in Norfolk, which was named after a person, just to make things more confusing.