gptfdisk: Add ONIE partition type GUIDs

Add GUIDs for two ONIE partition types:

   // Open Network Install Environment (ONIE) Boot Partition
   AddType(0x3100, "7412F7D5-A156-4B13-81DC-867174929325", "ONIE boot");

   // Open Network Install Environment (ONIE) Configuration Partition
   AddType(0x3101, "D4E6E2CD-4469-46F3-B5CB-1BFF57AFC149", "ONIE config");