ACPICA: Update behavior of CopyObject to match ACPI spec

Fixed a problem where a CopyObject to RegionField, BankField, and
IndexField objects did not perform an implicit conversion as it
should. These types must retain their initial type permanently as
per the ACPI specification. However, a CopyObject to all other
object types should not perform an implicit conversion, as per
the ACPI specification.

http://www.acpica.org/bugzilla/show_bug.cgi?id=388



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