xtensa: add core information for the de212 processor

DE212 is a general purpose xtensa processor without full MMU.
Core information files are autogenerated from the processor description
and are not meant to be edited.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>