i82801ix: Provide ramstage smbus functions.

Change-Id: Idc62e382a4002274abe6c23d76fe0874c62846c5
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/6433
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>