diagnostics: wilco_dtc: add syslog-tag for wilco_dtc crosvm instance

This syslog-tag will help differentiate wilco_dtc from other crosvm
instances in the syslog.

BUG=b:135448141
TEST=emerge-sarien diagnostics; cros deploy dut diagnostics; start
wilco_dtc; check for syslog tag in /var/log/messages

Change-Id: I28c155e0fa1d9938b9192eb89e386a49f6bd3a82
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform2/+/1662760
Tested-by: Trent Begin <tbegin@chromium.org>
Auto-Submit: Trent Begin <tbegin@chromium.org>
Commit-Queue: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
(cherry picked from commit 98f083add19231e12dc07164905979737e645cc5)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform2/+/1664531
Reviewed-by: Trent Begin <tbegin@chromium.org>
Commit-Queue: Trent Begin <tbegin@chromium.org>
diff --git a/diagnostics/init/wilco_dtc.conf b/diagnostics/init/wilco_dtc.conf
index 7e64f09..f84952d 100644
--- a/diagnostics/init/wilco_dtc.conf
+++ b/diagnostics/init/wilco_dtc.conf
@@ -99,6 +99,7 @@
          -p maitred.listen_port="${MAITRED_LISTEN_PORT}" \
          -p printk.devkmsg=on \
          --serial num=1,type=syslog,console=false \
+         --syslog-tag wilco_dtc \
          -c "${VM_CPUS}" \
          -m "${VM_MEM}" \
          -s "${RUNTIME_PATH}" \