KVM: arm64: Move NV-specific capping to idreg sanitisation

Instead of applying the NV idreg limits at run time, switch to
doing it at the same time as the reset of the VM initialisation.

This will make things much simpler once we introduce vcpu-driven
variants of NV.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20250220134907.554085-10-maz@kernel.org


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>