gpu-compute: Add missing include in dispatcher.cc

Due to some cherry-picking onto the release-staging branch, there was a
missing "sim/sim_exit.hh" include in "src/gpu-compute/dispatcher.cc".
This was causing compilation errors.

This is being added to the v23.0.0 release as a hotfix.

Change-Id: I1043ecf5c41ad6afc0e91311b196f4801646002f
Issue-on: https://gem5.atlassian.net/browse/GEM5-1332
diff --git a/src/gpu-compute/dispatcher.cc b/src/gpu-compute/dispatcher.cc
index d63c875..7b36bce 100644
--- a/src/gpu-compute/dispatcher.cc
+++ b/src/gpu-compute/dispatcher.cc
@@ -40,6 +40,7 @@
 #include "gpu-compute/hsa_queue_entry.hh"
 #include "gpu-compute/shader.hh"
 #include "gpu-compute/wavefront.hh"
+#include "sim/sim_exit.hh"
 #include "sim/syscall_emul_buf.hh"
 #include "sim/system.hh"