With GICv4.1, VMOVP is extended to allow a default doorbell to be^^^^^^
specified, as well as a validity bit for this doorbell. As an added
bonus, VMOPVP isn't required anymore of moving a VPE between
redistributors that share the same affinity.
Let's add this support to the VMOVP builder, and make sure we don't
issuer the command if we don't really need to.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>