dummy_resourcetable: make it built-in and standalone

The resource_table only makes sens to be present in the vmlinux, and not in
modules, so that it can be parsed by remoteproc.

So don't allow to build it as module and don't depend on dummy_remoteproc,
as one can build vmlinux without modules support.

Signed-off-by: Veaceslav Falico <vfalico@gmail.com>