ACPI, Add 64bit read/write support to atomicio on i386

There is no 64bit read/write support in ACPI atomicio because
readq/writeq is used to implement 64bit read/write, but readq/writeq
is not available on i386.  This patch implement 64bit read/write
support in atomicio via two readl/writel.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>