Fix definitions of existing cores and core importing script to follow
the rule of naming non-top level source files.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
The sample_controller core is a simple noMMU general purpose core, modern
analog of de212. It is used as a default core in the xtensa port of
Zephyr.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>