Event notification: pass CC priority map on creation

Event notification: pass CC priority map on creation

An event notification must have an associated clock class priority map
to indicate the ranks of its event's clock values.

As of this patch, a ctf.fs source component always set the priority of
all the parsed clock classes to 0.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>