x86_iommu/amd: Add interrupt remap support when VAPIC is not enabled

x86_iommu/amd: Add interrupt remap support when VAPIC is not enabled

Emulate the interrupt remapping support when guest virtual APIC is
not enabled.

For more info Refer: AMD IOMMU spec Rev 3.0 - section 2.2.5.1

When VAPIC is not enabled, it uses interrupt remapping as defined in
Table 20 and Figure 15 from IOMMU spec.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Tom Lendacky <Thomas.Lendacky@amd.com>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>