KVM: arm64: vgic-v3: Add ICV_EOIR1_EL1 handler

KVM: arm64: vgic-v3: Add ICV_EOIR1_EL1 handler

Add a handler for writing the guest's view of the ICC_EOIR1_EL1
register. This involves dropping the priority of the interrupt,
and deactivating it if required (EOImode == 0).

Tested-by: Alexander Graf <[email protected]>
Acked-by: David Daney <[email protected]>
Reviewed-by: Eric Auger <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Reviewed-by: Christoffer Dall <[email protected]>
Signed-off-by: Christoffer Dall <[email protected]>