Add Get Device UUID

Add support to get the UUID and return it in the specified
format per the IPMI Spec 2.0
diff --git a/apphandler.h b/apphandler.h
index 2957437..35a2b20 100644
--- a/apphandler.h
+++ b/apphandler.h
@@ -7,6 +7,7 @@
     // Get capability bits
     IPMI_CMD_GET_DEVICE_ID          = 0x01,
     IPMI_CMD_SET_ACPI               = 0x06,
+    IPMI_CMD_GET_DEVICE_GUID        = 0x08,
     IPMI_CMD_RESET_WD               = 0x22,
     IPMI_CMD_SET_WD                 = 0x24,
     IPMI_CMD_SET_BMC_GLOBAL_ENABLES = 0x2E,