xen: Add the Xen platform pci device

Introduce a new emulated PCI device, specific to fully virtualized Xen
guests.  The device is necessary for PV on HVM drivers to work.

Signed-off-by: Steven Smith <ssmith@xensource.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/trace-events b/trace-events
index 46a19d3..bebf612f 100644
--- a/trace-events
+++ b/trace-events
@@ -407,3 +407,6 @@
 
 # exec.c
 disable qemu_put_ram_ptr(void* addr) "%p"
+
+# hw/xen_platform.c
+disable xen_platform_log(char *s) "xen platform: %s"