systemc: Include eventq_impl.hh in scheduler.hh.

This ensures that we also get the inline definitions of some of the
methods defined in the EventQueue class. In certain circumstances gem5
won't link properly otherwise.

Change-Id: Ie0dfef207a165095bdfe1199cd1f690cebc4cbbf
Issue-on: https://gem5.atlassian.net/projects/GEM5/issues/GEM5-597
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29397
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/src/systemc/core/scheduler.hh b/src/systemc/core/scheduler.hh
index c9ca161..31cc35e 100644
--- a/src/systemc/core/scheduler.hh
+++ b/src/systemc/core/scheduler.hh
@@ -36,7 +36,7 @@
 
 #include "base/logging.hh"
 #include "sim/core.hh"
-#include "sim/eventq.hh"
+#include "sim/eventq_impl.hh"
 #include "systemc/core/channel.hh"
 #include "systemc/core/list.hh"
 #include "systemc/core/process.hh"