We don't expect to trap any GICv3 register for host handling,
apart from ICC_SRE_EL1 and the SGI registers. If they trap,
that's because the guest is playing with us despite being
told it doesn't have a GICv3.

If it does, UNDEF is what it will get.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240827152517.3909653-10-maz@kernel.orgSigned-off-by: Marc Zyngier <maz@kernel.org>