ACPI 6.3 added a 16-bit SPE overflow Interrupt field, replacing 2 of the 3 reserved bytes that are defined at the end of the GICC structure for 6.0. Add a new macro to initialise the new field. Signed-off-by: Pete Batard <pete@akeo.ie> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>