irqchip/gic-v3-its: Only emit VSYNC if targetting a valid collection

irqchip/gic-v3-its: Only emit VSYNC if targetting a valid collection

Similarily to the SYNC operation, it must be verified that the VPE
targetted by a VLPI is backed by a valid collection in the GIC driver data
structures.

Signed-off-by: Marc Zyngier <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Jason Cooper <[email protected]>
Cc: Alexandre Belloni <[email protected]>
Cc: Yang Yingliang <[email protected]>
Cc: Sumit Garg <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]