nodedev: Build a non-loadable driver lib

nodedev: Build a non-loadable driver lib

In order to test the nodedev driver, we need to link against a
non-loadable module. Similar to other loadable modules already in the
repository, create an _impl library that can be linked against the unit
tests and then create a loadable module from that.

Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>