ACPI: i386: bump to MADT to revision 3

ACPI: i386: bump to MADT to revision 3

Currently i386 QEMU generates MADT revision 3, and reports
MADT revision 1. Set .revision to 3 to match reality.

Link: https://lore.kernel.org/linux-acpi/20230327191026.3454-1-eric.devolder@ora
cle.com/T/#t
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Ani Sinha <anisinha@redhat.com>
Message-Id: <20230517162545.2191-3-eric.devolder@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>