APEI GHES: 32-bit buildfix

drivers/acpi/apei/ghes.c:542: warning: integer overflow in expression
drivers/acpi/apei/ghes.c:619: warning: integer overflow in expression

ghes.c:(.text+0x46289): undefined reference to `__udivdi3'
  in function ghes_estatus_cache_add().

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Len Brown <len.brown@intel.com>