trace: break circular dependency in event-internal.h

Currently event-internal.h includes generated-events.h,
while generated-events.h includes event-internal.h
causing a circular dependency.

event-internal.h requires that the content of
generated-events.h comes first, so that it can see
the typedefs for TraceEventID and TraceEventVCPUID.

Switching the TraceEvent struct to use uint32_t
for the two ID fields removes the dependency on
the typedef, allowing events-internal.h to be a
self-contained header. This will then let the patch
following this move event-internal.h to the top of
generated-events.h, so we can expose TraceEvent
struct variables in generated-events.h

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-9-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
