Given how tortuous and fragile the whole lack-of-GICv3 story is,
add a selftest checking that we don't regress it.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240827152517.3909653-12-maz@kernel.orgSigned-off-by: Marc Zyngier <maz@kernel.org>