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/data/boot_table.json b/data/boot_table.json
index 3b049f8..b38a9fb 100644
--- a/data/boot_table.json
+++ b/data/boot_table.json
@@ -739,7 +739,7 @@
         "lib_file_path": "utils.robot"
     },
     # Initiate host reboot using the Redfish API interface (GracefulRestart).
-    "Redfish Host Reboot": {
+    "RF SYS GracefulRestart": {
         "start": {
             "rest": "^1$",
             "chassis": "^On$",