ACPICA: FADT: Favor 32-bit FACS and DSDT addresses

If both the 32-bit and 64-bit addresses are non-null, use the
32-bit address. Provides Windows compatibility.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>