scripts/spelling.txt: add "partiton" pattern and fix typo instances

Fix typos and add the following to the scripts/spelling.txt:

  partiton||partition

Link: http://lkml.kernel.org/r/1481573103-11329-7-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index d73e9df..1145dc8 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -30,7 +30,7 @@
 
 #ifndef __ASSEMBLY__
 /*
- * ISA 3.0 partiton and process table entry format
+ * ISA 3.0 partition and process table entry format
  */
 struct prtb_entry {
 	__be64 prtb0;