[ARM] spelling fixes

Spelling fixes in arch/arm/.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/lib/bitops.h b/arch/arm/lib/bitops.h
index 5422510..2e787d4 100644
--- a/arch/arm/lib/bitops.h
+++ b/arch/arm/lib/bitops.h
@@ -47,7 +47,7 @@
  * @store: store instruction
  *
  * Note: we can trivially conditionalise the store instruction
- * to avoid dirting the data cache.
+ * to avoid dirtying the data cache.
  */
 	.macro	testop, instr, store
 	add	r1, r1, r0, lsr #3