boards: it8xxx2_evb: remove Renode simulation files

This platform was never supported in Renode, it's a leftover from Mi-V
support which probably was copied here. The referenced `it8xxx2_evb.repl`
does not exist in the Renode tree or in the `support` directory.

Signed-off-by: Patryk Koscik <pkoscik@antmicro.com>