Allow coreboot to initialize CMOS if checksum is invalid.

Allow coreboot to initialize CMOS if checksum is invalid.

If a file "cmos.default", type "cmos default"(0xaa) is in CBFS,
a wrong checksum leads to coreboot rewriting the first 128 bytes
(except for clock data) with the data in cmos.default, then
reboots the system so every component of coreboot works with the
same set of values.

Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Acked-by: Stefan Reinauer <stepan@coreboot.org>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6253 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1