update dontdiff file

Updates based on recent .gitignore updates:

*.o.*: Says Alexey Dobriyan:
These are presumably temporary gcc files, which aren't interesting.

setup.bin, setup.elf: new x86 boot code files (from Matthew Wilcox)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/dontdiff

@@ -18,6 +18,7 @@
 *.moc
 *.mod.c
 *.o
+*.o.*
 *.orig
 *.out
 *.pdf
@@ -163,6 +164,8 @@ raid6tables.c
 relocs
 series
 setup
+setup.bin
+setup.elf
 sim710_d.h*
 sImage
 sm_tbl*