Update redfish host graceful restart boot type

Changes:
      - Modify "Redfish Host Reboot" to "RF SYS GracefulRestart".
      - Update lib and test cases with new boot type name.

Change-Id: I8fe9c9569bb20810604a792263eb9f76eec66d16
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/redfish/systems/test_power_operations.robot b/redfish/systems/test_power_operations.robot
index 6fc7c22..bcfc854 100644
--- a/redfish/systems/test_power_operations.robot
+++ b/redfish/systems/test_power_operations.robot
@@ -46,7 +46,7 @@
     [Documentation]  Verify Redfish host graceful restart operation.
     [Tags]  Verify_Redfish_Host_GracefulRestart
 
-    Redfish Host Reboot
+    RF SYS GracefulRestart
 
 
 Verify Redfish BMC PowerOff