include: Fix spelling

Change-Id: Iadc813bc8208278996b2b1aa20cfb156ec06fac9
Signed-off-by: Martin Roth <martin.roth@se-eng.com>
Reviewed-on: http://review.coreboot.org/3755
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/include/pc80/mc146818rtc.h b/src/include/pc80/mc146818rtc.h
index 29e0348..170a433 100644
--- a/src/include/pc80/mc146818rtc.h
+++ b/src/include/pc80/mc146818rtc.h
@@ -22,7 +22,7 @@
 
 /* update-in-progress  - set to "1" 244 microsecs before RTC goes off the bus,
  * reset after update (may take 1.984ms @ 32768Hz RefClock) is complete,
- * totalling to a max high interval of 2.228 ms.
+ * totaling to a max high interval of 2.228 ms.
  */
 # define RTC_UIP		0x80
 # define RTC_DIV_CTL		0x70