boards: others: neorv32: add up5kdemo board variant

Refactor the existing NEORV32 board to become a UP5KDemo board variant for
the NEORV32 board. The software configuration of this board matches the
NEORV32 "UP5KDemo" processor template.

Signed-off-by: Henrik Brix Andersen <henrik@brixandersen.dk>
10 files changed