firmware_ECWakeSource: Don't provide timeout when hibernating EC

Currently, test uses 'hibernate 1000' command to hibernate EC, then
after 10 seconds (WAKE_DELAY) it wakes DUT by pressing power button.
Starting from CL:2442037 PSL hibernating with timeout is disabled
for NPCX. It causes EC to refuse hibernate with timeout and as a result
test is not checking if we are waking from EC hibernate.

This situation was fixed by hibernating EC without timeout. Test is
waking up DUT using power button, so timeout is not needed.

BUG=b:161775827
TEST=Flash EC ToT on casta. Run ECWakeSource test. Make sure that EC
     is hibernating without errors

Change-Id: Ifd857328d07e0fd423fe7a9fefc1c494f48f6593
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/2582043
Tested-by: Patryk Duda <pdk@semihalf.com>
Reviewed-by: Wai-Hong Tam <waihong@google.com>
Commit-Queue: Wai-Hong Tam <waihong@google.com>
diff --git a/server/site_tests/firmware_ECWakeSource/firmware_ECWakeSource.py b/server/site_tests/firmware_ECWakeSource/firmware_ECWakeSource.py
index cd804d1..28f0307 100644
--- a/server/site_tests/firmware_ECWakeSource/firmware_ECWakeSource.py
+++ b/server/site_tests/firmware_ECWakeSource/firmware_ECWakeSource.py
@@ -48,7 +48,7 @@
                                      self.POWER_STATE_RETRY_COUNT):
             raise error.TestFail('Platform failed to reach G3 state.')
 
-        self.ec.send_command('hibernate 1000')
+        self.ec.send_command('hibernate')
         time.sleep(self.WAKE_DELAY)
 
         # If AC is plugged during the test, the DUT would wake up right after