openpower: Add missing keyword in the test suite

Changes:
    - Added new keyword in the test suite

Tested:
    - Ran the test suite openpower/mpipl/test_mpipl_basic.robot
      successfully.

Change-Id: I36c9a08dd6061b959f9cf0fe05e42ba56c0b4538
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/openpower/mpipl/test_mpipl_basic.robot b/openpower/mpipl/test_mpipl_basic.robot
index 8ae534d..767b98d 100644
--- a/openpower/mpipl/test_mpipl_basic.robot
+++ b/openpower/mpipl/test_mpipl_basic.robot
@@ -144,3 +144,12 @@
     ${sys_dump}=  Redfish.Get Properties  /redfish/v1/Systems/system/LogServices/Dump/Entries
     Log To Console  System dump generated: ${sys_dump['Members@odata.count']}
     Should Be True  ${sys_dump['Members@odata.count']} == 1  msg=No system dump generated.
+
+
+Clear All Subscriptions
+    [Documentation]  Delete all subscriptions.
+
+    ${subscriptions}=  Redfish.Get Attribute  /redfish/v1/EventService/Subscriptions  Members
+    FOR  ${subscription}  IN  @{subscriptions}
+        Redfish.Delete  ${subscription['@odata.id']}
+    END