scripts: gdb: move MNT_* constants to gdb-parsed

scripts: gdb: move MNT_* constants to gdb-parsed

Since these are now no longer defines, but in an enum.

Link: https://lkml.kernel.org/r/20250618134629.25700-2-johannes@sipsolutions.net
Fixes: 101f2bbab541 ("fs: convert mount flags to enum")
Reviewed-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>