kvm-all: Pass requester ID to MSI routing functions

Introduce global kvm_msi_use_devid flag plus associated
kvm_msi_devid_required() macro. Passes the device ID,
if needed, while building the MSI route entry. Device IDs are
required by the ARM GICv3 ITS (IRQ remapping function is based on
this information).

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Message-id: 1474616617-366-5-git-send-email-eric.auger@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>