Reverting back the redfish poweron changes in secureboot

Reason : Redfish Power On is a blocking call and
         wait till Host reaches running state

Secureboot tests needs non blocking call which just triggers
power on and continue validating the other expectations

Signed-off-by: Lakshminarayana R. Kammath <lkammath@in.ibm.com>
Change-Id: I8e20e07793abc2bb9ab477511b194289b210a474
diff --git a/openpower/secureboot/test_secureboot.robot b/openpower/secureboot/test_secureboot.robot
index dbfaa5b..f275c0f 100644
--- a/openpower/secureboot/test_secureboot.robot
+++ b/openpower/secureboot/test_secureboot.robot
@@ -213,8 +213,7 @@
     Log  ${error_log_path}
 
     # Starting a power on.
-    Redfish Power On  stack_mode=skip  quiet=1
-    Set Auto Reboot  1
+    BMC Execute Command  /usr/bin/obmcutil poweron
     Wait Until Keyword Succeeds  15 min  15 sec  Error Logs Should Exist
 
     #TODO: This will be enabled little later as more tesing required