gdb: Modify gdb prompt when running gdb_grub script

This will let users know that the GDB session is using the GRUB gdb scripts.

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

grub-core/gdb_helper.py.in

@@ -2,6 +2,10 @@ import os
 import re
 import subprocess
 
+def prompt_hook (current_prompt):
+  return "(grub gdb) "
+gdb.prompt_hook = prompt_hook
+
 ##### Convenience functions #####
 
 class IsGrubLoaded (gdb.Function):