PWM: Correct misspellings of "module" in context of PWM

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: Heiko Schocher <hs@denx.de>
diff --git a/drivers/pwm/pwm-imx-util.c b/drivers/pwm/pwm-imx-util.c
index f92c370..285564a 100644
--- a/drivers/pwm/pwm-imx-util.c
+++ b/drivers/pwm/pwm-imx-util.c
@@ -2,7 +2,7 @@
  * (C) Copyright 2014
  * Heiko Schocher, DENX Software Engineering, hs@denx.de.
  *
- * Basic support for the pwm modul on imx6.
+ * Basic support for the pwm module on imx6.
  *
  * Based on linux:drivers/pwm/pwm-imx.c
  * from