Revision 3790

Replace #ifdefs for sc520 systems by run time probing.

fixes #109

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Signed-off-by: Peter Stuge <peter@stuge.se>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>