On some boards including bob, sand and pyro, tast.TPMResponsive is failing since R72-11175.0.0.

Stainless:
https://stainless.corp.google.com/search?view=matrix&row=test&col=build&first_date=2018-10-10&last_date=2018-10-23&master_builder_name=master-release&branch=master&test=%5Etast&board=bob&exclude_cts=false&exclude_not_run=false&exclude_non_release=true&exclude_au=true&exclude_acts=true&exclude_retried=true&exclude_non_production=false

Blame list:
https://crosland.corp.google.com/log/11174.0.0..11175.0.0

Log:
2018/10/19 23:01:08 Started test platform.TPMResponsive
2018/10/19 23:01:37 [23:01:36.773] External command failed: exit status 134
2018/10/19 23:01:37 [23:01:36.773] Command: tpm_version
2018/10/19 23:01:37 [23:01:36.774] Uncaptured output:
[WARNING:trunks_factory_impl.cc(158)] Failed to initialize the trunks IPC proxy; trunksd is not ready.
[FATAL:trunks_client.cc(353)] Check failed: factory.Initialize(). Failed to initialize trunks factory.

Aborted (core dumped)
2018/10/19 23:01:37 [23:01:36.774] Error at tpm_responsive.go:28: Failed to run tpm_version: exit status 134
2018/10/19 23:01:37 [23:01:36.774] Stack trace:
Failed to run tpm_version
	at chromiumos/tast/local/bundles/cros/platform.TPMResponsive (tpm_responsive.go:28)
	at chromiumos/tast/testing.(*Test).Run.func4 (test.go:189)
	at chromiumos/tast/testing.runAndRecover.func1 (stage.go:68)
	at runtime.goexit (asm_arm.s:1015)
exit status 134
2018/10/19 23:01:37 Completed test platform.TPMResponsive in 30.432s with 1 error(s)
https://storage.cloud.google.com/chromeos-autotest-results/250105926-chromeos-test/chromeos6-row2-rack3-host5/tast/results/tests/platform.TPMResponsive/log.txt

ps.txt:
https://storage.cloud.google.com/chromeos-autotest-results/250105926-chromeos-test/chromeos6-row2-rack3-host5/tast/results/tests/platform.TPMResponsive/faillog/ps.txt

ps.txt suggests trunksd is down.
trunks    1315  0.0  0.0      0     0 ?        Zsl  22:54   0:00 [trunksd] <defunct>


I could not find suspicious changes from the blame list though. The only change about trunksd is "Install trunks fuzzers and fuzz them on ClusterFuzz"
https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/ef32c54842cb37e4976f5dc2f1a6bc836ac1265e