KVM: arm64: Advertise NV2 in the boot messages

Make it a bit easier to understand what people are running by
adding a +NV2 string to the successful KVM initialisation.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20250220134907.554085-6-maz@kernel.org


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