x86_64: fix typo in acpi_pm.c

Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/clocksource/acpi_pm.c

@@ -71,7 +71,7 @@ static struct clocksource clocksource_acpi_pm = {
 	.rating		= 200,
 	.read		= acpi_pm_read,
 	.mask		= (cycle_t)ACPI_PM_MASK,
-	.mult		= 0, /*to be caluclated*/
+	.mult		= 0, /*to be calculated*/
 	.shift		= 22,
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,