pc: Enable MSI support at APIC level

Push msi_supported enabling to the APIC implementations where we can
encapsulate the decision more cleanly, hiding the details from the
generic code.

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/hw/apic.c b/hw/apic.c
index 4eeaf88..5fbf01c 100644
--- a/hw/apic.c
+++ b/hw/apic.c
@@ -19,6 +19,7 @@
 #include "apic_internal.h"
 #include "apic.h"
 #include "ioapic.h"
+#include "msi.h"
 #include "host-utils.h"
 #include "trace.h"
 #include "pc.h"
@@ -862,6 +863,8 @@
 
     s->timer = qemu_new_timer_ns(vm_clock, apic_timer, s);
     local_apics[s->idx] = s;
+
+    msi_supported = true;
 }
 
 static void apic_class_init(ObjectClass *klass, void *data)