ACPICA: Split acpi_format_exception into two parts

Split acpi_format_exception into two parts. New
function is acpi_ut_verify_exception and will be used to
verify exception codes returned by user.

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>