Added support for ffdc_report_list_path for use by plug-ins.
Added support for ffdc_report_list_path for use by plug-ins.

Plug-in programs may write file names to the file named in
ffdc_report_list_path.  These file names contain additional data that is
to displayed in the defect report.

Change-Id: Ie1178de742fbdf0cf3fab391397d0ad7aedf512e
Signed-off-by: Michael Walsh <10404802c7de463f402c4a18638106ca1b12ef61@us.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation