time/jiffies: Rename ACTHZ to SHIFTED_HZ

Ingo noted that ACTHZ is a confusing name, and requested it
be renamed, so this patch renames ACTHZ to SHIFTED_HZ to
better describe it.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1343414893-45779-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/linux/timex.h b/include/linux/timex.h
index 99bc88b..7c5ceb2 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -232,7 +232,7 @@
  * estimated error = NTP dispersion.
  */
 extern unsigned long tick_usec;		/* USER_HZ period (usec) */
-extern unsigned long tick_nsec;		/* ACTHZ          period (nsec) */
+extern unsigned long tick_nsec;		/* SHIFTED_HZ period (nsec) */
 
 extern void ntp_init(void);
 extern void ntp_clear(void);