Revision 2772

Add a common/global failover.c file which can be used by all
(or at least most) mainboards. This should put and end to
copy-paste'ing the same file again and again for every mainboard.

Fix the build for the MSI MS-6178 target (wrong location of the common
failover.c file).

Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Corey Osgood <corey.osgood@gmail.com>