Add a way to check PE/COFF image machine type

xtldr/modules/pecoff/includes/pecoff.h

@@ -17,6 +17,10 @@ EFI_STATUS
 PeGetEntryPoint(IN PPECOFF_IMAGE_CONTEXT Image,
                 OUT PVOID *EntryPoint);
 
+EFI_STATUS
+PeGetMachineType(IN PPECOFF_IMAGE_CONTEXT Image,
+                 OUT PUSHORT MachineType);
+
 EFI_STATUS
 PeGetSubSystem(IN PPECOFF_IMAGE_CONTEXT Image,
                OUT PUSHORT SubSystem);