[IA64] spelling fixes: arch/ia64/

Spelling and apostrophe fixes in arch/ia64/.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 3549c94..c478449 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -791,7 +791,7 @@
 early_param("additional_cpus", setup_additional_cpus);
 
 /*
- * cpu_possible_map should be static, it cannot change as cpu's
+ * cpu_possible_map should be static, it cannot change as CPUs
  * are onlined, or offlined. The reason is per-cpu data-structures
  * are allocated by some modules at init time, and dont expect to
  * do this dynamically on cpu arrival/departure.