Fix for error logs test cases

Changes:

    - Cleared error logs after system power on
    - Increased the wait time for PEL log to get acknowledge
      from HOST

Tested:

    - Ran test cases successfully from openpower/pel/test_bmc_pel.robot

Signed-off-by: dnirmala <dhurgam.nirmala1@ibm.com>
Change-Id: I20c4f4b48837b9273be0ed4410443f2c8e5a68ee
diff --git a/openpower/pel/test_bmc_pel.robot b/openpower/pel/test_bmc_pel.robot
index 3964d66..07fa494 100644
--- a/openpower/pel/test_bmc_pel.robot
+++ b/openpower/pel/test_bmc_pel.robot
@@ -201,6 +201,8 @@
     [Tags]  Verify_Host_On_State_From_PEL
 
     Redfish Power On  stack_mode=skip
+    Redfish Purge Event Log
+
     Create Test PEL Log
 
     ${pel_ids}=  Get PEL Log Via BMC CLI
@@ -963,7 +965,7 @@
     # Check host transmission state for the cases where PEL is
     # expected to be  offloaded to HOST.
     Run Keyword If  "${expected_transmission_state}" == "Acked"
-    ...  Wait Until Keyword Succeeds  2 min  10 sec
+    ...  Wait Until Keyword Succeeds  5 min  10 sec
     ...  Check If PEL Transmission State Is Expected  ${pel_id}  Acked
 
     # Adding delay before checking host transmission for the cases where PEL is